Tuesday, June 26, 2012

BATTERY JUMP SHIFT





Of all the lithium chemistries available, we’ve found the LiFePo4 based lithium cells to offer the best combination of safety, stability, cycle life, power, and energy density. Though slightly less capable in terms of energy density per kilogram, the trade offs of much more stable and safe operation, and the very much longer life expectancy of these cells have made them a favorite.

Of the LiFePo4 cells, the A123 cells are often offered as the mark to beat. We have not found it so. We early on identified the Sky Energy large format prismatics in 100Ah and 180Ah sizes as much more convenient to build into an electric vehicle and offering a flatter discharge curve and long life when compared to all other cells on the market.

Sky Energy received a large investment from the China Aviation Missile Academy, a government entity, and became the China Aviation Lithium Battery Company (CALB). They continued production of the Sky Energy design as the SE series of cells which we have used successfully in a number of builds.

In June, 2012, CALB is introducing their new CA series of cell, notable by its newly designed grey case. Commonly referred to as the “grey cell” this introduction has been eagerly awaited since its announcement well over a year ago.

EVTV has developed a reputation for ruining the party at Lithium battery celebrations by actually performing direct first party testing on cells – often to destruction.

In this comparison, we do NOT perform any direct testing but provide a comparison of the SE and CA series cells based entirely on data provided by CALB, which we’ve found in the past to be quite reliable. Indeed, if we have a criticism, it is that CALB tends to hide their light under a bushel, seeming almost hesitant to make claims for their product.

In this fashion, they have very modestly provided us a spreadsheet of almost puzzling data that on further examination, would seem to hide a stunning advance in LiFePo4 cell quality. We are not at liberty to share the spreadsheet, but rather here present our best take on it, with excerpted graphics.

We do of course plan an entire series of episodes presenting EVTV test data to support or refute these claims. But if past experience holds true, we look forward to discovering performance quite beyond their claims, and we are genuinely excited to examine this new incremental advance in cell chemistry.

It should be noted that it is our intention to begin distribution of these cells through the EVTV online store at our web site. And so we may be viewed as something more than a disinterested party in the matter.

That said, note that we chose the battery, the battery didn’t chose us. Indeed, subsequent to our rejection of the head of their marketing groups desire to establish a U.S. marketing slogan - CALB – Cost A Less Bill, we have never successfully had a relationship with CALB for advertising or sponsorship at all. Indeed, our humorous response to this suggestion must have lost something in translation as he was pretty seriously offended by it. None intended of course.

Despite this, we’ve remained enthusiastic over their SE series and have sent many conversions their way. With the advent of this new CA series, and the ongoing difficulty our viewers have in finding reliable trusted sources to purchase lithium cells from generally, we have painfully arrived at the conclusion that we not only have to sell the batteries ourselves, but stock them in our facility at a somewhat enormous capital expense.

We intend that the immediate impact of these cells will simply be better cars, better conversions, and better results for our viewers. As they demonstrate these very desireable vehicles to their friends, neighbors, and relatives, we believe the demand for electric vehicles will be accelerated and the adoption of electric vehicles in America will within a few short years comprise over half of all vehicle sales.

In the short and the long of it, the story of DIY conversions in America since 2008 has been all about one thing – the enabling power of the batteries. We believe we enjoy SUPERIOR batteries to those used by Tesla, Nissan, and General Motors in every respect. These cells have allowed electric cars to cross the threshold of viability, moving DIY conversions from semi-interesting science projects, to actual drivable useable automobiles, in one smooth move.

The introduction of the CA series represents an incremental, but quite important advance in these cells, and consequently the cars that use them. They really do NOT offer any particular advance in energy density and thus range. But we believe they will provide greater power, longer life, more consistent capacities, better thermal characteristics, and much improved cold weather performance. This represents a kind of maturation of the chemistry, and we find these kinds of improvements really more important than range. Our cars go further than we do now. But longer life, better power output, less heat, better performance in cold weather are all extremely valuable characteristics at this point.

One feature we expect is not provided in the test data, but we intend to test it. Part of the process, and the delay, in introducing the new grey cells was some pretty serious behind the scenes advances in the scale of cell manufacture through the building of newer, larger, and more automated production lines for these cells, enabled by the financial backing received from the government.

This would appear at first glance to hold nothing for the end user/purchaser of the cells.

But one generally overlooked aspect to cell management is the fact that we don’t use cells in cars at all. We use STRINGS of cells in our cars. And our range, and our performance, and our power output can never exceed, to even the slightest degree, the abilities of the LEAST capable cell in the string. You can have 35 cells capable of 10,000 amps of power and a 1000 mile range. If you have one cell limited to 200 amps and 30 miles, your car will never travel more than 30 miles, nor accelerate at a rate greater than 200 amperes can deliver.

I would much rather have a string of cells rated at 180 Ah where each and every cell showed exactly 170Ah capacity, than to have a string where all the cells actually tested at 200Ah, except for two at 165Ah. A more consistent string is easier to charge and discharge safely and effectively and will provide better range and performance simply by being consistent.

So one of the less obvious aspects of the CA cell is CONSISTENCY – what do we actually get out of the box in terms of capacity from one cell to the next. And with these larger, more automated, more efficient assembly facilities, we would expect to see a more consistent product – leading to much improved cell strings in our cars. We intend to actually test this against a box of undisturbed SE cells we have on hand.

And now the bad news. At this point, the erosion in cell prices appears to have not only stopped, but reversed in some ways. CALB, now well financed, has been very stuck on pricing and we are seeing some firming in the other companies as well. Some second tier cells were going as low as $1 per Ah for a few months, but that appears to be over and if anything cell prices appear to be rising slightly.

While we don’t see this trend holding long term, in the immediate future we seem to have formed a “bumpy bottom” in LiFePo4 cell prices. We would love to see a dramatic decrease to half the price in the near future. But it appears to be wishful thinking at this point. In increasing capacity to meet demand, the expenses incurred appear to have put battery manufacturers in a kind of lithium vise. They face ever increasing over capacity and competition, with an inability to deliver cells at any price lower. And so we see their marketing efforts turn hopefully and expectantly to large purchasers for Wind farm and grid power applications. It remains to be seen if this works out for them, but the DIY EV market appears to not offer sufficient clout to drive discounting. We face more likely abandonment than price decline.

Again, we intend further direct testing in the future. But this should provide a peek at what is claimed for these cells on introduction.


HIGH RATE DISCHARGE PERFORMANCE

All LiFePo4 cells have a stated capacity usually in ampere-hours (AH). We currently carry the CA180FI and CA100FI cells that feature a stated capacity of 180 Ah and 100Ah respectively.

This amp hour rating is measured at a defined rate of discharge of 0.3C. The 100Ah cell would provide 100 ampere hours at a rate of 30 amps. The 180 Ah cell would provide 180 Ah at 54 amps.

At higher discharge rates, the capacity available is decreased. In the SE series of cells, you could expect at a discharge rate of 3C or 300 amps for the 100 amp cell, a capacity of 94% or 94Ah. In the CA series, this is much improved at 97.7% capacity at 3C. Your 100Ah cell will still have nearly 98 Ah at 3C compared to 0.3C.

The charts below compare the CA60FI and the SE60AH cells for high rate discharge performance.





THERMAL INCREASE

All LiFePo4 cells exhibit a rise in temperature when discharging. The internal process of intercalating lithium ions has certain inefficiencies that show up as heat. At low discharge rates this is of course minor but as the discharge rate increases, so does the heat gain.

At 3C, the SE cell series shows an increase in temperature of 22.6C.



This is actually pretty good. The cells have proven to need no particular cooling at all. They are quite hardy up to about 65C where one of the electrolytic solvents begins to deteriorate.

So at ambient temperatures of 30C for example, an increase of even $25C leaves us at the 55C level. And they cool rather quickly under lower discharge rates. So even under heavy acceleration, we've found cooling of these cells just not necessary. Indeed, they perform better up around 45-50C.

But thermal gain is a sign of an efficiency loss. For the CA series, this is dramatically decreased to a temperature increase of 8.6C. Internally, the CA series is just much more efficient than the SE series. And this points to even more durability and likely longer life under high accelerations and power demands.




POWER DENSITY

One of the more important factors in LiFePo4 cells is their ability to deliver power (current) on demand. We usually relate the number of amperes a cell can deliver with the corresponding decrease (sag) in voltage. More properly, this is measured as POWER DENSITY in Watts per kilogram at various levels of state of charge (SOC)



This chart compares the power density of the SE40AHA, the SE60AHA and the CA60FI cells.

At a 50% state of charge, the SE40AHA shows a power density of 890 W/kg while the SE60AHA shows 779 W/kg. The CA60FI shows 1322 W/kg – a 70% increase over the SE series.

We were able, for example, to discharge the SE180Ah cells 1000Amps with about a 22% voltage sag when testing the Speedster Redux with a Soliton1 controller. This would imply that the CA series cells could deliver 1700 amps in the same situation.

The spec sheets on the new CA series cells have thus far been spotty, conflicting, and incomplete. The SE cells we used to rate at 8C at EVTV. We would conservatively claim 12C on the CA series from this data, and we will attempt some sort of testing as soon as practicable. This is a little difficult on these large format cells. Even the 100 Ah cell would thn require a 1200 amp load to prove this.


COLD TEMPERATURE CAPACITY

One of the disadvantages of LiFePo4 cells compared to other lithium chemistries is a rather sorry performance in cold weather. While not nearly as debilitating as it was in the old lead acid battery era, the decrease in capacity of LiFePo4 cells is very much a factor.

At a temperature of -20C, and a discharge rate of 0.3C, the SE series of cells will provide 71.9% of capacity. Your 100Ah cell will provide a discouraging 72 amp-hours at that temperature. This is of course even worse at higher discharge rates.

The CA series cells provide a dramatic improvement in cold weather performance with 87.49 % of the original capacity. Your 100 Ah cell now provides a little better than 87 Ah at -20C or -4 degrees Fahrenheit at a 0.3C discharge rate.




CYCLE LIFE

One of the most important advantages of LiFePo4 cells compared to other lithium chemistries and certainly with Pb chemistry cells is their very long life. We measure this life in the number of expected charge/discharge cycles to 80% discharge and until the cell exhibits 80% of its original capacity..

This is projected by doing several hundred charge/discharge cycles at 1C and to 100% depth of discharge and extrapolating the data to the point where the cell exhibits 80% of its original capacity. This calculation is also improved by assuming an 80% depth of discharge instead of the tested 100%.

At 290 cycles to 100% at 1C, the SE series cells show about 85% of original capacity. The CA series has upped that to about 91%. This represents a huge increase in cycle life for the CA series cell.




Assuming that this had extrapolated to a 2000 cycle life at 80% DOD, the new cells would imply 3300 cycles. For 3000 cycles at 70% DOD, the CA cells should see 5000 cycles

The result appears to be a bit of a huge leap in battery performance at a very minimal increase in price. So while prices have not really come down, we're getting more battery per ducat in a number of very interesting ways.

After a period of relatively static lack of movement in battery cells over the past year, we are enormously excited by this new introduction. After seeing this data, we are attempting to triple our investment in stock on hand on the assumption that these cells will be very much in demand for the foreseeable future.

We intend to ship all cells with our braided cell strap with Nordlock washers

Jack Rickard

Sunday, June 24, 2012

HEARTBEAT

Tesla made their July 2012 delivery date in grand style on June 22. Video of the event HERE.

This week, I could not help but comment on both the paramilitary precision with which they are executing this very heartfelt dream, but also the audacity of what they propose.

By way of comparison, the Audi A8 ($78,000) and BMW 750i ($84,000) are really very similar cars in all respects. Their appearance is very close to the Tesla, in weight they are similar, and most of all in price they are similar.

BUt the Audi sold 5700 cars in the U.S. last year and the BMW750i only sold 11,299. That Tesla would introduce a new sedan, otherwise similar but with range - limited electric drive and expect 20,000 sales the first year borders on the preposterous.

I think if they fall short, it will be by inches.



Beyond that, it's all good news. Already this weekend since we shot the video they did release some weights and the Model S is somewhat more porcine than I discussed at over 4600 lbs. That makes their 375 Wh/mile look considerably better.

As for us, we suffered the thrills of victory and the agony of the feet all in one week with the Elescalade.

Jeff Jenkins of EVnetics kindly provided two circuit designs to spoof our MAF and MAP signals. I had pretty much came to the same chip with the Manifold Pressure Signal and in fact had one built. But we needed a voltage controlled oscillator design for the Mass Air Flow signal badly and he came up with a good one.







In any event we obtained the parts and I clumsily soldered the little circuits together onto some bread board and wired them into the vehicle.

Along the way testing them, we just went to hell on tachometer signals. First, we lost our THIRD Westach 702-12R we've had on this project. Maybe our voltage is a little high at about 14.5v, or maybe our magnets are two strong, or I don't know what. But we blew up two pronto and the third lasted about two weeks during very light testing.

This is the hall effect magnetic pickup we use to send an RPM signal to the Soliton 1's. So we bit the bullet and went with EVnetics recommendation for an Automation Direct AM1-AP-3A inductive proximity sensor. Turns out to be a pretty good recommendation. This sensor will pick up bolt heads or gear teeth or anything ferrous. We tried it on our magnets and it worked great. Plus it has a little LED that flashes each time it pulses so you can visually see it working. We loved it. We've added it to the online store HERE. It's certainly the one to use with the Solitons.

Once we had that on, we could START and idle again. But our sensor for the Escalade reluctor ring was acting up and it needed to be impossibly close to the teeth to do anything. We actually obtained a replacement on the chance that the one we had was faulty. No luck. We finally got it aligned, but it would drop out as we increased rpm. The mounting plate was apparently vibrating. So we remounted that with a piece of rubber ROOFING TAPE.
It improved dramatically.

And so. With both sensor spoof circuits, and both tachometer sensors working, we were FINALLY able to start the vehicle simply by setting the key to IGNITIION, and then START. The Solitons fired up the motors and quickly reached an idle of 600 rpms.

Without the MAP and MAF sensors, when we would accelerate, the ECU would quickly throw a diagnostic trouble code and slam the throttle plate to idle. It then sent an advisory to the screen in the dash - REDUCED ENGINE POWER. Well hell yes its reduced, you've reduced it to idle.

But with the MAF and MAP sensors deployed, it seems satisfied for the moment to allow us to accelerate using the throttle.

Let's talk about the circuitous route all that takes. The accelerator sends an accelerator position signal to the ECU. The ECU sends a throttle drive signal to the throttle, and receives a throttle position signal back to the ECU. We use the TPS as a throttle INPUT to our two Solitons through an opamp buffer. The Solitons then actually drive the motor of course.

By the time we get out of the opamp, our whole range of throttle signal is 1.9 to 4.3v. So the throttle feels a little "touchy".

Fortunately, the Solitons have another adjustment where you can set the amount of power provided at half throttle. We reduced this from the traditional 50% of power at 50% throttle to 35% power at 50% throttle.

This gave us much finer control at low rpms. Of course, having 35% range on the lower half of the pedal position leaves 65% remaining power for the LATTER half of the pedal throw. But you should expect this sort of tuning "for feel" on any EV project.

This also interplays with the amps/sec ramp rate on the Soliton. You can set this from a couple of hundred amps per second up to say 5000 amps per second. This is the rate at which the SOliton will ramp up power to the motors. Too fast a rate and you snap axles. Too slow a rate and your pedal feels sluggish and delayed.

In any event we FINALLY got it all cobbled together to the point where we could get in, turn the key to IGNITION, and here we have to pause for just a second or so delay for the contractors to close and the SOlitons to come up. We're going to add an LED to the dash using the Soliton RUNNING output to signal this "ready" situation but you can hear the contractors. Then to START. We had of course located the signal the ECU sends to the starter on the gasoline engine, and wired that into the Solitons AS a START signal.

The Solitons run up the motors and quickly find the 600 rpm idle speed. Note that we have all of this going to TWO Solitons and two motors. I cannot detect any unusual hunting for rpm or "fighting" between the two systems to bring it to idle. They appear to work very well in tandem this way. Of course we have all the other settings setup identically as well with the exception of the optional OUTPUT gage drivers. But given the PID circuits in the Solitons really act independently, we did not know whether they would "play nice" with each other or not. But it appears they work VERY WELL together. While we have two motors, they are on the same shaft and we have ONE tachometer signal, whenever we can keep one running.

With the MAP and MAF sensors in place, and the crankshaft position sensor, the ECU seems reasonably happy. We can very smoothly accelerate up to about 3500 rpm which is as high as I can bear with it loaded only by the torque converter. It is quite smooth, both in acceleration, as well as vibration and noise. The blowers on the motors make more noise than the motors of course but the entire installation is very nearly vibration free.

At idle, the system draws between 11 and 14 amperes at 188 volts. That's a 2kW idle which means without air conditioning, just turning the motors and the power steering/brake pump, we use 2 kWh per hour sitting there. Not a great feat of efficiency in an electric car. As this car will probably average 750 Wh per mile, idling for an hour would be the equivalent of about 3 miles range. Viewed in that way, it's not too bad.

And so early Friday afternoon, we went to shoot some video of all this and explain our sensor spoofing. Just as we turned it up, we heard a loud pop and everything went dead. We never did find the pop. But it took three hours to figure out what happened. We had NO 12 volt power. Our rear DC-DC converter read about 2.5volts. If we disconnected the load from it, it was happily 14.5volts. But when we hooked the load back up, 2.5volts.

We entered three of the most frustrating hours of troubleshooting I've encountered in some time. If we pulled the fuse block, we were at no load of course and had our 14 volts. So we assumed something was loading the circuit heroically. We put the fuse block back on and pulled EVERY SINGLE FUSE one by one and every relay on the fuse block. To no avail.

After three hours, we discovered that our battery box, which we had used as a ground for the rear DC-DC converter, and which had always worked fine, really didn't have a ground to the frame of the truck. We could READ the DC=DC voltage as long as no load was applied, but it couldn't supply any significant current at all as it had lost a good ground connection. This is about the fifth time I've cured something that was driving us crazy on this truck with a GROUND solution. ALL the grounds in the wiring harness are there for a purpose and needed. They do not tie together at some central point. If you miss one, you have a problem. In this case it was OUR added equipment, but it didn't matter. A ground was the solution and it fixed it completely.

Of course, that meant we got to shoot the segments of the video looking into the Elescalade at about eight o'clock at night and THEN do the broader segments on Tesla et al.

Do I sound like I'm complaining? Fear not. I'm in my salad days here. In the first place, I LOVE it when something is screwed up and I can't figure out what it is. The day everything just works and there is nothing to troubleshoot is the day I walk out of the garage and the end of your weekly fix of EVTV. I only play on the frontier of things. I don't do well with "townies."

But this was a very good day of winning milestones along the way. I am totally devoted to the concept that everyone should drive magnetically driven personal transportation - electric cars. I don't actually think we need to give UP anything. We can play with ICE vehicles as antiques for the next 200 years. If we got half the people to do HALF their miles electrically, the world is just entirely different in so many simultaneous good ways that it will be incredible to watch this all unfold.

But I almost singularly REALLY DO understand how technological change happens in our population. And this change falls almost entirely on two factors. The first is, you have to have DESIREABLE cars that are lusted after by early adopters. And second, you have to have information sources to disperse that info to the population - better trusted sources. TV advertisements and press releases don't cut the mustard in this case.

If anyone is to adopt an electric car, his first official act will be to talk to someone he trusts who actually lives with one. Let me reiterate, the check ain't a happening thing until I talk to probably SEVERAL people who live with the new technology and clearly gain advantage by it. That's manno a manno kemosabe. A super bowl ad won't do it. No first person recommendations, no check. And I have to be persuaded the first person is not a copper foil helmet kook who is also trying to keep his dog from reading his mind.

Tesla has built a plant in Freemont California to mass produce an all electric all aluminum sleek looking European sedan with enough computer power in it to edit my videos on. Lust.

We build Speedsters which are automatic head turners. I can't go to the grocery store without hearing about it. The Elescalade is a POWER demonstration of the same thing. It imprints the concept of ANY car. It's not a very practical example for most. But it will be impressive.

And the cars you build, from a Porsche 914 to a VW THing, to a GT-40 right down to a 1939 Dodge Brothers half ton pickup truck and yes, including a Glastron power boat, where done well, are a demonstration of the same thing. And YOU are a first person trusted source to dozens and potentially hundreds of people around you.

I cannot adequately express, or persuade or put into words how very powerful this is. It is NOT the usual gratuitous "if we all join forces together" power to the people bunch of horse shit that many of you would be perfectly willing to accept. EACH one of you has ENORMOUS power to influence others by the dedication of your ducats and handwork to this cause. It actually causes CONSTERNATION in the populace. Gas prices are this. Cars are that. We are told this. We know that. But then how come this old man in Lexington Kentucky can make a 1939 pickup truck run on no gas? And he seems HAPPY with it. What if it doesn't go as far as he wants to? Ah, but what if it does?

Pebbles in a pool? How about a small block V-8 dumped into a bathtub. The effect you guys have on the world INDIVIDUALLY is so far beyond what you are aware of it is nearly comical. CUMMULATIVELY I don't even know what it means. You are unaware giants walking among aboriginal pygmy dwarves. While they watch TV, you build your electric car. While they whine over every ducat, confident in their knowledge of the cost of everything and the value of nothing, you spend on parts they can't comprehend after you've explained it. If you don't know what it DOES what difference does it make what it COSTS?

The mission is not to put every one into a 1939 electric truck. It is not that everyone can afford a Tesla and should have one. It is to make them WANT one. It is to build desire, awareness, and demand. The design. The manufacture. The costs and the pricing. All follow from demand. It is not the other way around. Demand doesn't build as the costs fall. The costs fall BECAUSE of the demand.

You guys are the flag wavers. We've had flag wavers in the past. They mostly waved the flag. They didn't actually buy or build electric cars. They were "activists" and "environmentally aware" and they even "demonstrated". Largely in futility and yes, I dismiss their efforts as almost entirely salutary and trivial. The sum total of them all wouldn't warrant 12 minutes out of one of my days. Lots of people have truly profound opinions on what others should do with their money to make the world better for us all. Noise. And not very useful noise frankly.

But when you commit to a project to convert an existing car to electric drive, pursue it to completion, and then demonstrate it to all who have an ear to hear and an eye to see, the effect is sufficient to change the world on its path. And I am pretty much personally committed, 24x7 and with every breath drawn, to aid and abet you on this mission where and how able.

Whether you do or not, I know who and what you are. And there are not yet enough of you. There will be more...

Meanwhile we struggle with the twelve blind men around the elephant effect, each struggling to describe in words what an elephant looks like. Brandon Hollinger believed he liked electric cars. This week, he upgrades his Saab96 from lead to LiFePo4 and now has lithium underfoot on the road. The difference is the difference between a science project and a car. And now he knows ALMOST as much as his mother does about electric cars. (She drives a lithium Miata). The Saab went 119 miles and had 30% SOC left and it gets scratch on takeoff now. As he drives this daily, the marvel will grow - not subside. And if he thought he had drank the kool-aid before.....

The heart of this is the marvel that becomes a mantra "If people just KNEW about this, they would...." That's the feeling I get every single day.

Spread the word...

Jack
Editor Rotundus

Friday, June 15, 2012

A Little Bit of Sunshine and the Tesla Stockholders Meeting.

If you can't tell from this week's video, I've become something of an Elon Musk/Tesla fanboy. We kind of stole a largish portion of their video for today's show. Unfortunately it had some Beat of the Butterfly Wings" music in it that caused us to be banned on YouTube. We have a scant thousand YouTube viewers anyway - mostly those with technical problems with the JWPlayer we use or Apple in general. But the YouTube thing is a constant pain in my battery box. If HTML5 ever gets fully deployed, YouTube will go away at EVTV.






I found the presentation fascinating on a number of levels. Musk was clearly having fun and enjoying the day, and why not? He was delivering early with a car he is clearly pleased with. Of course, there are many questions, but he seems to have better visibility of them than before.

A couple of points I picked up on:

SAFETY: Not my hot button frankly. But of course the key element of the deliveries on June 5 and 6th were that the cars were legally production deliverable. This was because they had passed ALL the regulatory hurdles to reaching that state.

You might recall that the Tesla Roadster caused a Federal fine of $244,000 that Tesla was forced to pay for not having an EMISSIONS CERTIFICATION CERTIFICATE. They had, rightly I think, assumed that since they did not HAVE any emissions, they did not need certification. In fact, to get certified, you have to go on a dynamometer and do an exhaust system sniff test. This isn't even possible to accomplish with a Tesla Roadster. It has no exhaust.

DOesn't matter said the government. You don't really have to pass an emissions test, but you DO have to have the certificate - ergo the fine. What a kuntry.

Musk of course has several very small children and pictures the car as a car HE will drive. Busy with the whole new daddy thing, safety is an issue. They had just completed the crash testing and he was clearly gratified with the results. His issue, not mine. But being against safety is kind of like being against puppies and kittens. Not much future there particularly if you ever want to get laid again.

SALES AND HANDLING. These do not appear to be related. I do relate them. And Musk clearly does as well. One of the things we have learned over and over is that there is a huge disconnect in electric car discussions. It involves a disconnect between those that have driven a good one, and those that have not. And never the twain shall meet.

There is something indefinable in driving an electric car. I have variously and at various times ascribed this to the lack of noise. Or the continuous feeling of acceleration. Or to the very low center of gravity. Or to the sound it DOES make while continuously accelerating. Or....

In truth, I don't know what it is. It is the center and soul of the EV grin. You can't help but smile the first time you feel it. It's a thing your face does automatically and you have no control over it really. What actually causes it I don't know.

In designing the Model S, they did several things that starting with a blank sheet of paper you CAN do with electric drive and you CANNOT do with an ICE car - so no one does.

They put the entire drive train where it belonged, where it drives the wheels. The rear axle and motor and controller all got strangely confused in this car. It is basically a fat rear axle.

That one feat leads to a very unusual car. It has no engine up front. Worse, it has none in the rear either. Polar moment of inertia of mass, or the angular mass, is a measure of an object's resistance to changes to its rotation. The moment of inertia of an object about a given axis describes how difficult it is to change its angular motion about that axis. Therefore, it encompasses not just how much mass the object has overall, but how far each bit of mass is from the axis. The further out the object's mass is, the more rotational inertia the object has, and the more rotational force (torque, the force multiplied by its distance from the axis of rotation) is required to change its rotation rate.

Hmmm. Wikispeak. What this means is that the rotational stability of a car about a central axis roof to floor in the center, is a function of the DISTANCE of the proportions of mass from that center. The car will handle better with the mass in the center than it will at the two ends. With a front engine car, a lot of mass is far forward and with a rear engine car, of course to the rear. This is why MID ENGINE sports cars handle better. And it's why the usual strategy of putting batteries WAY up front and WAY in the rear do not help your vehicle's handling characteristics. IT becomes much less stable and more likely to spin out in a turn.

With the Model S, there is no big mass in the front, and no big mass in the rear. And in fact, most of the mass is in the center. People and Batteries are both in the center between the wheels and in fact the batteries are BENEATH the floor of the car. This contributes a movement of the CENTER OF GRAVITY as well to a very low point, probably beneath your ass level.

The combination of these two have simply not ever BEEN seen in an automobile - lacking perhaps the milk lorries in the United Kingdom during the 1930's. Nobody can design a car with THAT low a center of gravity and that minimal a polar moment - until now.

If you couple that handling characteristic with the usual elements of an EV grin, you have a driving experience that you cannot describe because there is no analogue to it. You've either felt it or you haven't.

So far extremely few have. And therein lies a tale. Tesla did a very smart thing several years ago. They started taking deposits to gage interest in the car. But unlike Nissan with their $99 salutary refundable deposit, Teslas wa a pretty handsome$5000. I'm number 2873. But they now have 10,000 reservations in hand or 50 million in deposits.

Those serious enough to put down a $5000 deposit a year or more in advance all share one thing in common. NONE of them have ever driven the car. Musk of course has. And so he has a kind of double EVgrin.

He gets to grin from driving it. And then he gets another grin when he contemplates that he has $50 million in deposits for the car from people who have never driven or felt it. If 10,000 people will plunk down $5000 for a chance to drive a car that looks a lot like what modern European sedans look like these days, what would people who actually got to test drive the vehicle do? And so he's pretty confident he can sell 20,000 of these next year. His only concern is can he PRODUCE 20,000 of them next year.

I don't know that it will be THAT easy. In Missouri we say that it takes a mighty big dog to weigh a ton. And 20,000 is a BIG number when you get into the stratified air of the premium auto market - particularly at the $87,000 level. That's the number that keeps surfacing on an attractively equipped 300 mile range version. I was kind of hoping those would come in at $77,500, which I predicted two years ago would be the price of their $50,000 Model S.

But then again, I've never driven the car.

Just a few months ago I faulted Tesla for announcing a proprietary charging plug. I hadn't quite thought that through I'm afraid. If you are going to do a fast charge in less than an hour on an 85 kWh battery pack, and we had that number then, you are pretty much talking about at least 85 kWh of power through the cord by definition. Musk urges us to think 100 kW. Makes sense.

Neither ChaDemo or the hugely ungainly SAE combi plug proposal can do that level of power, more like half. So our existing combating fast charge standards, will quickly NOT only not be standardized, but won't even charge our cars of just a few years hence if we do get better batteries. How many charge standards do we have to go through here?

Musk claims they have a small attractively engineered plug that can do 100kW of power. That would be an engineering design win all by itself.

Once the 9600 bps modem was released and available, nobody really cared about the 2400 bps standard again. Similarly at 19,200. New technology that offers a significant perceived advantage wipes out standards where they stand. If there's one thing better than a 100 mile range car that can charge in an hour, it's a 300 mile range car that charges in an hour.

In our last episode we talked about what it might take to put a fast charge station every 40 miles on all 47,300 miles of U.S. interstate and came up with a figure of $59 million at $50K per station. I found this an epiphany for me personally.

Now here is Musk, smugly alluding to the Supercharge Network he doesn't want to talk about, but is dying to talk about because he is so excited he's almost jumping up and down.

One of Musks other companies is Solar City. They basically have broken the mold on solar installations by financing the installation and tacking it onto your home mortgage. Your mortgage payment goes up, your utility payment goes down, and you put nothing into it at all. Really ever. The next buyer then pays off the mortgage at the sale.

This little financial innovation has caused Solar City to grow about as fast as they can hire people and buy trucks. They will be doing an IPO I'm told later this summer if the markets are favorable. I really thought Feed In Tarriffs were the way to go to get the solar thing off the ground. Solar City kind of made up their own and are doing well anyway.

Legacy legislation continues to confound and amaze new technologies. In California, it is actually illegal to sell electricity. This is part of the monopoly afforded the utility companies. So you can't take your electricity, mark it up, and sell it to your neighbor. This all kind of made sense in 1918. But doing charge stations for profit becomes a little problematical. The charge station manufacturers have invoked a theory that you are simply charging for access to the station - not the electric grid. That's a little bit thin if not outright dubious. I can see a battle in the future that could be really ugly.

But if you make your OWN electricity and sell it from your own grid, I'm not sure how that all reads. If you made electricity from solar, and stored it in batteries, and sold that to cars, I guess I'm not seeing a problem here. Who can object to what?

California has 8600 miles of "primary" highway out of their 16,800 miles of roads. If you put one every 100 miles, and sprinkled a handful in San Francisco, San Jose, Los Angeles, and San Diego, you could probably come up with about 100 charge stations. They would be a little more expensive with solar and batteries. But at a half a million apiece, that would be $50 million and at $1 million apiece that would be $100 million. And that's not necessarily money down a hole like free public charging stations. Let's say it was $20 to "fillup." I'd pay it. Say the average fillup was 60kWh. In California that's about $18 worth of electricity anyway from the grid. So paying a flat fee of $20 isn't' even an inconvenience.

Good work if you can get it. You're selling sunshine for 30 cents a kilowatt-hour. If 20,000 cars fill up twice a week, we are looking at $38.5 million a year income from an initial investment of $100 million. Each station has to charge 57 cars per day at that 60 kWh. That's 3420 kWh from 4.5 hours of sunshine or a 760 kW array. That's pretty big frankly. I don't know you can do that with batteries for $1 million. But with 38.5 million per year and a more realistic 10 year cap rate, we probably can for $3.85 million per station.

This can scale anywhere you want it to. If Musk just did it in California, and with Solar City's ability to purchase large amounts of solar panels, their costs have to be down around 85 cents per kWh, would this business model catch on nationally? I wouldn't' actually mind some of that action.

This ignores COMPLETELY that gasoline stations don't make squat on gasoline at all. ALL their income comes from Twinkies and cokes. We ARE talking about people charging for an hour. What do you have for them to do? Drink coffee and soda. Go to the rest room. Eat. Get online.

Suddenly, the necessary infrastructure looks like a business opportunity instead of a charity event or a place for our government to spend more money.

And the ability to swap batteries in one minute? Oh yes. For those in a hurry. At a bit of up charge. But that's not what that's really about.

What if we sell you an $87,500 Tesla Model S for $67,500 (less $7500), and you can join our SuperCharge network and let us worry about the batteries on the monthly plan. You were going to spend $600 per month on gasoline? Well, how about $400 per month with us for so many miles. Kind of like a cell phone plan.

Solar City is thriving by making the pain go away from installing solar. If we take that lesson and apply it to the electric vehicles, would we be looking somehow for a DIFFERENT outcome?

Guys it is true that Tesla is NOT going to franchise the sale of their automobiles. They are going to own outright all of their own stores and control the sales process totally.

Why then wouldn't' they want to own all of the gas stations that fuel them as well? Solar powered gas stations. Delivering electricity. To Electric cars. Without the pain. Ding dongs and Ho-Hos akimbo.

This thing grows into a huge, vertically integrated recurring revenue engine of unimaginable proportions. Actually unfathomable. The vision is breathtaking both in scope and detail and I am in awe.

Starting to feel the squeeze? He said he was going to make it hurt.

Wanna play "who is smart enough to be an OEM?" and other games for children and the geriatrically feeble minded? I'm talking about you Bob.

We've UPPED our game. Now up yours!

Monday, June 11, 2012

Missing Week And Elescalade Blues

My wife informed me last Thursday evening that she was going to Fort Lauderdale to graduate with her Doctorate Degree from Nova Southeast University. She was leaving Friday morning at 11:00. As it turns out, none of her daughters were going to be able to make this celebratory event. Sigh. So she guessed she would just go by her self....

So I wasn't here Friday. Or Saturday. Or Sunday until pretty late.

I'm back. Don't travel as well as I once did. But it was a good event and a big milestone for her. She teaches up at Southeast University here and I guess all the other girls had PHd degrees and she seemed to think it important.
Really she's always been there for me. Not sure why the graduation ceremony itself was important, but apparently it was to her.

The Elescalade is fighting us every step at this point. We're a bit behind on our updates. We've had the motor spinning for about three weeks but that's not the half of it.

First, we could not seem to get a TACH input IN to the two Soliton 1's. The sensor we had hard installed in the adapter plate would not produce a waveform when we hooked it up to the SOliton's 12v output, PGND, and TACH.

And it didn't appear to matter how we did it, one Soliton or two, which one, or what pull-up resistor we used.

So we got ANOTHER sensor, a couple of magnets and hooked it all up to the reluctor ring mounted on the front of the motor. We quickly just connected to switched 12v, frame and ran the signal to the Soliton and checked it. Sure enough, both Soliton's showed RPM on the inputs and at 2 pulses per turn, the right RPM at that.

So we mounted the magnets more permanently, built a proper bracket for the sensor, and i got some 4 wire shield thinking I was doing a good thing. Ran the three leads all the way up to the Soliton and again connected to 12v, PGND, and TACH.

It didn't work. We tried everything. One Soliton. The other SOliton. Both Solitons. 2 ppt, 4 ppt, 6 ppt. They did not recognize a signal.

So we got a THIRD sensor and hooked it up to 12v switched, frame, and ran just the signal to the SOlitons. Worked fine. We started to hard wire THIS one and I noticed that this was our last sensor on hand. STOP. Let' just mount it. Leave it on 12v and frame.

And that seemed to take care of it. I would guess that the Soliton's are eating our sensors. But I don't know how or why. And since I'm having difficulty getting anything to show the same symptoms twice this week....

We got the motors to where when we went to IGNITION, they would light up and cycle contractors and all looked good. Then when we went to START, the 12v START signal wired into input 1 would in fact cause the two motors to spin up and then settle back to idle at about 450 rpm. Both are idling. Both are pulling current. Total amp draw on the pack at idle is 11 amps with no air conditioning.

But the tachometer on the instrument panel didn't budge. So we played with the MAP sensor input and the CAM position sensor input. Finally, the crankshaft position sensor, which reads the reluctor ring, was 1/16 from the teeth. A 1/32 too far apparently. I wobbled it around and suddenly we got a shaky tach signal. After playing with the mounting for an hour or so, and getting it so close it almost made noises as the teeth passed, we got a tach signal.

Sounds like a good thing. Except the ECU got a tach signal as well. So when we would step on the throttle, it would slam the throttle position plate back to idle quite forcefully.

I'm no longer doing anything intelligently. Just hooking up wires to various things trying to get a symptom to change. IF I set the %1 output to MOTOR CURRENT, routed it through a 750 ohm resistor, and fed it as a manifold pressure signal (MAP) we could start, idle and run the RPM up and down about three times, then it quits and forcibly sets up back to idle.

The MAP signal is a 0.8vdc to 4.5vdc signal representing vacuum in the manifold of course. At idle, it should be 0.8vdc and wide open it should be 4.5vdc. Vacuum looks like a nearly linear function of RPM, but all of our RPM was pulse signals and not many pulses per rotation at that.

MOTOR CURRENT works at the bottom when you are turning up. But once you get to 2400 rpm or so, the current drops off and so the voltage. So we are higher RPM with lower manifold pressure indicated. THE ECU notes the discrepancy and shuts us down hard.

The throttle position signal actually starts too high. We run from about 2.0v to 4.3v out of the TPS and we are using that successfully for the throttle input to the SOliton's. The opamp puts out plenty of current. But we start at mid range for the MAP signal. So this doesn't work at all.

I fear if we get this part playing, then it will want the MAF signal. Etc. etc.

I'll try to put together some video this week.

Oh, the Helwig brushes are in and on the web site store. We're adding NordLock washers to the kit. They're pretty nice actually. Mylar sleeves. Four leads. We've got 12 sets for the Warp 9 and 12 sets for the Warp 11 and it takes awhile to get them in. These are the H60 Redtop split brushes made famous by Tim Catellier and the Catellier effect. First come. First shipped. When they're gone, it's a good three weeks to get any more.

Also, I see NO reason to discuss why I think you might want a fire extinguisher for your eCobra or other conversion. Why bring those things up at all. In any event, I found a cool 2 1/2 lb ABC perfect for those late night Interstate shoulder cookouts. It's chrome and comes with bracket. Rated for automotive.

Jack Rickard

Sunday, June 3, 2012

Hydrogen Gods and the Nieuwe Elektrische Boot

This week you get a twofer as I didn't post a blog with last week's show. I was gonna.... and....see....what happened was.....see....

Actually, it is embarrassing. THe sheet with the data on it for the follow up test still lays next to the motor. Every day I was going to bring it home and do the blog. Still there.

So we don't know WHAT happened. Actually we did get our answer. It just wasn't a very dramatic or satisfying one. It appears that 57% of the gain in efficiency comes from the material, and 43% or thereabouts comes from the split brush design. So you need it all.



I also have yet to receive my order of Helwig brushes, so we can't make them available. A couple of viewers have already asked about ADC motors. Yes, Helwig Makes them. No we'll probably not carry them.

We did a lot of wiring on the Elescalade this week but I didn't shoot any of it. It's just wiring. The starter to the START input and the J1772 circuit to another Soliton input and a bunch of 4/0 cables that were a pain to make up. I can spinet the motor, but there are problems.

The worst of the problems is the tach signal. The Soliton insists we don't have one. I've tried 1.5.1 and version 1.5.2 of the software and it just doesn't pick up the tach. This is VERY frustrating as we tested THAT tach on THAT adapter plate with THAT soliton a dozen times on the bench. In the car, with the motor turning, no input according to the log program. I've got a little hand held oscilloscope I've bought that is a marvel. Of course I don't know how to use it. It has about seven buttons on the whole thing and no clue what they do. I'll have to actually read the book. I detest that. Males should NOT have to read instructions.

Maybe my pull-up resistor is bad. We do have three magnets now instead of two. But the Soliton has pulse settings for both 3 pulses per revolution and 6 so that can't be it. IF it is a bad sensor, which as I said we tested numerous times, this is horrifying news. The entire motor assembly, and everything we've stacked on top of it, would have to come out. I'd rather give myself a root canal with a wine corkscrew.

Somewhat more serious is a glitch with the ECU. With the pickup hooked up to our reflector ring, the ECU cycles the throttle position back to off about once a second no matter the accelerator position. Reviewing the Cadillac manual, I find that in comparing the crankshaft position signal (RPM)to the manifold pressure, if they don't match, the system purportedly throws a Type A DTC. I'm not certain, but I think that means it sets the throttle plate to minimum. I'm GUESSING here. But it would appear we do need the manifold pressure signal.

Fortunately, the MAP sensor puts out a pretty simple voltage between 0.2v and 4.5v indicating manifold pressure. I'm thinking we can take the MOTOR CURRENT output and scale this 12v pwm signal to a 0-4.5v dc that might correspond. MAYBE if I do it with a potentiometer voltage divider, I can get it to spoof close enough to the expected signal to make it work.

The system also uses mass air flow and indicated engine coolant temperature in some calculations. But they appear to result in TYPE B DTCs and I don't' think those are as serious. I plan on putting the engine coolant temperature probe in the moutning bolt hole on top of one of the motors to get a digital read of motor case temperature on my normal display. But the MAF signal is a 2000-9000 hz 5v square wave. I can do this, but it would take an old function generator or something on voltage controlled oscillator mode. Kind of complicated.




So we spent a lot of time this week on wiring and mysteries and troubleshooting and there's not a lot to show. We'll work some of this out and hopefully be able to recap a bit next week


For this weeks' show I let our viewers bail me out. We had a visit from Mike Orr of Cincinnati who has made a J1772 EVSE box. He sold one for $650 and didn't really make much on it so he wants to ask $750 or $790 for them. Problem is, it is a 25 amp system and it would have to be MORE to get it up to 70 amps, which would be useful. As there are readily available EVSE now at hardware stores for $1000, this is kind of a loser. But we tested his box on the Escalade and it worked fine. It looks great. It's hell for sturdy. And it's quite small.

Andrew McClarey did some of our video graphics when we upgraded our intro. He had a nice build of a Fiber Fab Valkyrie he stole on eBay. Well, it's gotten nicer. He originally did this in lead and was trying to convince me lead was where it was at. I of course was trying to convince him that LiFePo4 was where it was at and that lead was dead. As it turns out, he has a brand new set of CALBS in the car now and WOW does it make a difference. He and a buddy are also working on a BMS that does have kind of a cool looking display.

Royce Wood of course continues on his Couger. But he's also doing a conversion for a friend of his. Royce, but a camera. I don't like your camera. But I do like the conversion. Royce has advised us on some of the intricacies of the Cadillac. He has operated an auto repair service for many years. And he's now getting into conversions. Where did you hear about this model - three years ago? It's happening.

In last weeks episode I talked about maybe doing a boat at some point. Anne Kloppenberg of Amsterdam was here at EVCCON last year and is just a HOOT to be around. This guy just spews energy and enthusiasm. He's done pretty well installing solar panels in Amsterdam. But he was talking about converting an old Glastron speed boat to electric drive. THIS week he sends us some video of the first run. It DEFINES the concept of the EV Grin. Literally WOOH - WOOH MAMA - LOOKY WHAT I BUILT.. as he speeds across the water at 53 km/hour with the sound of the prop, but NO engine sound at all.

This is cool for us. But cooler for him. I'd like to have an electric boat here on the Mississippi. But in Amsterdam, they are very down on you spilling that oil slick from your gas or diesel engine all over their canals. Quite environmentally conscious there as well. The only CO2 they want in the air is that that comes from burning Marijuana. They actually made CIGARETTE smoking illegal there, but EXEMPTED Marijuana smoking from the law.

And so Anne faces a serious business opportunity in making electric speed boats. The demand could be huge.

Finally, I riff a bit on hydrogen. You will be surprised to learn that my first love was not electric cars but hydrogen. Hydgrogen may be God and I am certainly of the religious orders surrounding it. It has one proton, and one electron. It is unity. It is the lightest element, and it comprises 75% of the mass of the universe, unless you buy into dark matter theory. Yes, 75% of everything is hydrogen. IT is the most reactive substance in the universe. The party girl of elements, it will combine with ANYTHING.

Therein being the rub. You have to PRY it lose. And it becomes a heroic loser as a fuel for personal transportation. I mean HEROIC. I got in a riff with some truly off planet types on LInkedIN that turned into a huge personal attack because I wouldn't buy into their hydrogen promotion efforts. So it was game on and I was slashing back. But it took me back a few years and my utter fascination with hydrogen.

I still think it holds the secret to all understanding of the universe. I just don't think I want to be in a car with it. Too many steps. It is, to say the least, inelegant in personal transportation.

EVCCON 2012. We've finished our first discount increment as of June 1. I am delighted to report, and a bit frightened to contemplate, that we have 125 registrants for the convention scheduled Septermber 26-30 and 29 cars. As we had a total registration of 128 and 28 cars INCLUDING ALL OF MINE at last years event, we are already larger than we DID last year. Today being the 3rd day of June, 2012 Year of Our Lord.

The basic math is 375-400 attendees and 50-60 cars. But my trade show experience indicates something else. We always said you cannot have a trade show for 300. It's the number you can't have. If you get to 300 industry insiders having a meeting, there will inevitably be 700 others show up to watch them. That's why you can't have 300. You can have 100. You can have 200. You can have 250. You could probably have 275. And then you can have 1000. But you can't HAVE a convention of 300.

This is like King Liunitis and The Battle of Thermopylae. Yes, there were indeed 300 Spartans. But what gets forgotten is that there were also 700 Thespians that came to watch.

As 125 of you discuss your plans to attend, the cars you're bringing, the side meetings you're going to set up, etc. It just causes the 700 to want to come watch all the more.

Fortunately Brain saw this coming and has put us in the ShowMe Center Arena. ├čo we'll have lots of room. But I don't really know where this goes in 2013.

See you there.

Jack Rickard

Monday, May 21, 2012

Escaladus Interruptus and the Catellier Effect

This week, we were hard at work in the 2008 Electric Cadillac Escalade EXT conversion and we are at a very rewarding phase of the build where things move along quite quickly.

Tim Catellier of Chandler Arizona slipped in and mounted a small explosive device under the hood and this kind of wrecked our week.

Tim, an EVCCON 2011 attendee, and so of course a rank up in standing over "ordinary" viewers, inquired about a pleasant little puzzle he was having with his BMW Z3 conversion. He had been at EVCCON 2011 with his erstwhile assistant, his FATHER, and we were privileged to examine first hand and up close the particulars of this Zilla/Netgain build using CALB cells - excellent in all respects. He in turn claims the drag racing and autocross was the most fun he'd had in a car EVER with his pants on and no music.

It seems he had developed a "frame leak." I'm actually extraordinarily pleased with this. We had done a show that prominently featured our efforts to chase down a frame leak on the 2009 Mini Cooper Clubman. We described what they were, how you could detect them, why it was important for your personal safety NOT to have one, and how to chase them down. We have since had a regular flow of viewers who HAVE found frame leaks subsequently.
While most were minor leaks in the 30 ma range, some have been serious. So I'm kind of pleased this particular episode caused a lot of people to check their systems for leaks, and more pleased that they have largely been successful in addressing them. I'm not precisely a safety Nazi. Life's a bitch, and then you die, and ho hum. But this one has caused us some nasty shocks in the past and so it deserved some attention. Apparently the problem was not as rare as I thought. It wasn't just us. And so, as Marthaa Stewart says, "That's a good thing."

The check is simple. Connect a multimeter between any battery terminal and frame ground. You should see a varying voltage of 4 to 6 volts. It will probably jump around. This is because the pack "floats" separately from frame ground. If you read ANY steady voltage above a volt or so, you have a frame leak. If you read DIFFERENT steady voltages based on which battery terminal you measure to ground, you certainly have a frame leak.

If you connect a 12v light bulb between the terminal and the frame and it fails to light, it is probably a very minor leak of 30 or 40 ma usually through some of your instrumentation. If you get any light, you have a serious situation that can be life threatening in the right environmental conditions - like sweaty skin.

In any event, Mr. Catellier had one. ANd after carefully and logically troubleshooting the problem, isolated it to the MOTOR. DC series motors of course have brushes and a commutator. Carbon conducts. And a buildup of carbon dust within the motor is not unusual. Sufficient carbon dust can short the field windings to the case. Actually this is so common that a leak of less than 30 ma is not even considered a problem by the motor manufacturers. Tim's was more in the 800 ohm range which into a pack his size, is pretty stout.

He tried blowing the motor out with compressed air and failed to eliminate the problem.




George Hamstra, of Netgain Motors had previously rebuilt this same motor and wanted a clean slate on this problem. After examining photos of the brushes, he asked Tim to send in the motor and he shipped him a brand new motor from Warfield, complete with the latest Helwig H60 RedTop brushes.

It was a non-trivial amount of work to swap out the motor. But Tim again enlisted the aid of his erstwhile assistant, DAD, and they were able to do it in some four and a half hours. The frame leak was gone. And they reassembled the car.

He was back on the road and drove it to work and back the next day. But there was an interesting difference. Tim had kept careful records over the past 26 months and tracked energy usage, electricity costs, gasoline prices, and right down to the dollars dimes and ducats saved in not purchasing gasoline, all in a handy spreadsheet, just as a proper Computer Systems Administrator is wont to do.

The car averaged 380 Wh per mile for over two years. In fact, Tim and I had actually had a conversation earlier about this as we have a pretty strong rule of thumb that a car will use about 1 Wh of energy to move 1 Mile over time and average, for each 10 lbs of car. Tim's car weighed in at EVCCON 2011 at 3285 lbs. And 380 Wh/mile somewhat exceeds our rule of thumb. I was unable to account for this or provide a persuasive theory. Maybe my rule of thumb not so good medicine in all cases.

On his drive to work and back, Tim noted an energy usage of 280 Wh/mile. This is kind of dramatically better.

He describes this somewhat better than I do on his blog at http://evz3.blogspot.com/

I received an e-mail message regarding this. In discussing the issue, he refined his results with total driving over the past 680 miles - 332 Wh/mile average. At 3285 lbs, I like this number for by now obvious reasons.

I initially suggested that the only thing I could imagine would cause such a DRAMATIC disparity in two otherwise identical 11 inch motors was the advance timing. The Netgain motors come marked with alignment marks for CCW, N, and CW timing. This corresponds to counter clockwise as viewed from the drive end of the motor, neutral, and clockwise respectively.

Most explanations of electric motor theory are technically correct as far as they go, but of necessity incomplete. First, some of the factors are difficult to explain. And second, after 150 years some of them we really don't know exactly. For some reason, "square" motors - that is motors with a certain ratio between diameter and length, run better than others. A certain amount of mass of iron in the case is simply required for efficient operation. We CAN make motors lighter. That's not necessarily a good thing. We know that the field windings set up a magnetic field that causes armature rotation. But were you aware that there is an interaction where the armature rotation then affects the magnetic field - in fact rotating it in the direction of the armature?

This is termed the armature effect and actually we DO know quite a bit about this. In the Netgain Warp 11HV, they employ inter poles to counteract the effect of this, and this is how this particular motor can handle higher voltages without arcing.

In the ordinary Netgain Warp 11, the CCW position literally rotates the brush ring a few degrees in the direction of armature rotation. This moves what is termed "the neutral plane" that same number of degrees. And so the brushes are only truly at neutral when the motor reaches a couple thousand rpm and the armature effect comes into play. Since it is OUT of neutral at low rpms, you would think this would cause arcing on startup. But in fact, the actually applied voltage to the motor is very low at that point and so arcing isn't as much of a problem. Under power AND RPM, the voltage is higher, and so that is where we want the brushes to truly be in the neutral plane.

And so we refer to this as ADVANCE TIMING. My theory was that if Mr. Catellier had his first motor accidentally at N or worse CW timing position, this would cause severe arcing during acceleration - and probably a LOT of carbon dust. That could seriously undermine his Wh/mile and explain his frame leak.

Unfortunately, brilliant though it sounded, it was another case of my trying to type myself smart in a fashion that would make the DIYElectric crowd cheer with pride.

Tim had of course noted and recorded the position on both motors. CCW. Theory busted.

Leaving what? The brushes. I'm accustomed thinking of brushes as just brushes and that their main characteristic is their life span, based on the hardness of the material. This also becomes a factor in seating the brushes, as they can take longer or shorter amounts of wear to properly seat in. But once they are in operation, there is little to choose between them other than how many miles you get before you get to change them. The technology is 180 years old. What's to know?

But in the spirit of rational inquiry, what else is there? That was the notable change between the two motors.

I happened to have a Netgain Warp 9, and an ADC 8 motor on a bench I had cleared off. We reassembled the Warp 9 using the new Helwig H60 Redtop brushes and painted the motor. The ADC took a little more work, we bead blasted the end bells, (and the armature unfortunately), revarnished the armature, and replaced the brushes and the entire brush mounting ring. I intend to use it on a lawn mower.

But we looked around and found the old brushes from the Netgain Warp 9. I wired up a JLD404 meter and a digital voltmeter with a contactor, one of our A123 13.5volt modules, and a switch. And we ran the motor with the new brushes, that had about 10 hours of seating on them. Then we changed the brushes to the old brushes. As it turns out, these aren't Helwig brushes at all. They are marked ML1683 and ML1684 H8 with a stylized chevron with a capital N in it. I have not determined who the manufacturer is, but Tom Brunka advises that it is a low voltage brush used on fork lift motors typically at 72v and below.

So we ran the motor again with the old brushes. The difference was astounding. For the same 129Ah of energy, the new brushes ran for 3 hours 38 minutes and 54 seconds. The old brushes ran for three hours, one minute, and 25 seconds.

So we reran the new brushes again. Along the way, we began recording RPM and commutator temperature along with current and voltage. The results are shown below.




If you clear out all the chaff, the new brushes use 485 Wh per hour to turn the motor at 2652 rpm while the old brushes require 535 Wh per hour to turn the shaft 2053 rpm. This is such an astounding difference that there must be something HUGE wrong with our methodology.

Except it rather persuasively reflects, in both direction and amplitude, what Tim Catellier reports.

I really have no further explanation for this. Here is the data and we would be very interested in direct attempts to reproduce either refuting or supporting. In the meanwhile, if you are driving a Netgain Motor a year old or more, you might invest in a set of Helwig H60 RedTops. Baseline your Wh/mile, change the brushes, and measure again. We would be very interested in what you find.

The current Helwig part numbers are:

For the Warp 9 = 10-621117-674-3-01
For the Warp 11 = 10-621117-674-3-02

I think Netgain is offering these brushes now at $150 per set of eight brushes. We will try to do the same on the EVTV online store as soon as possible.

We have also chased down the XSTURBOS guy and ordered 10 of his Garret blowers. We'll put together a little kit with the blower, the shroud for the motor to mount it on, and a relay at $495. George Hamstra of Netgain has already spoken for one for his Bricklin build that we are hoping to see at the EVCCON 2012. But hopefully we'll have these up on the web site this week or next as well.

Why? The main defense you have to carbon dust buildup in the motor is the motor fan. The newer motors actually have an improved fan on the drive end and these fans do a pretty good job at moving air through the motor, both to cool it and to clear the inevitable carbon dust. The problem is, that works real well at 3000 rpm. It works not so well at 300 rpm. And at 20 rpm it doesn't do squat. We have routinely begun using these 434 cfm blowers on all our Netgain motors. Any more heat you can remove is a good thing. And at low rpms, you still have fairly impressive air flow to remove carbon dust as well as heat.

Many people have run Netgain motors for years quite handily without an external blower. So this is overkill EVTV style. Still we recommend it.

Additionally, there are many less expensive blowers that are out there that will do just fine as auxiliary blowers for the motor. These look cool. For what i'm spending on the Escalade build, looking cool is kind of required.

Your mileage may of course vary....

Jack Rickard

Sunday, May 13, 2012

Messin with Wires.

This week we mostly deal with wiring issues on the 2008 Cadillac Escalade EXT Electric. The motors are in and we spun them up using a 12v A123 battery module. Very quiet and vibration free.

We mounted two glycol fill bottles, one for our Soliton liquid cooling system and one for the electric heater. It has been over a year since we did the segment on our tankless water heater we are using to heat both cockpit and battery boxes. We'll repeat a lot of that in the next few weeks as we install it. But the big breakthrough is the realization that we could use the windshield washer heater switch to turn it on.





The Cadillac actually has a heater for the windshield washer bottle. I've never heard of this before. And I don't quite get it. The idea of dumping hot windshield washer solution on an iced up windshield gives me a chill, so to speak, windshields costing what they do. The thermal contrast between the heated solution and the ice is pretty great. I would think they would have some problems with fracturing windshield glass.

The system IS under recall, but for another reason. IT has burned a couple of Cadillacs to the ground. The problem is, they don't fix it in the recall. THey just disconnect it and you no longer have a heated windshield washer. We haven't exactly done the recall, but I do intend to disconnect the power to it. It goes through a 60 amp fuse on the fuse block.

Leaving a rather unused, but really quiet prominent switch on the console right below the environmental controls. And so we are going to steal this signal and use this switch to turn on our electric heaters.

The heater assembly we created has pump, TWO contractors, and two heater elements all in one box. We'll use the signal from the switch to turn on the pump and the heater elements. Relays and thermostatic switches will be used to cut OUT each of the heating elements in turn as the temperature of the system rises..

In this way, we'll turn them both on initially. When the temperature gets to 45C, we'll cut one of them off with the thermostat. As it continues to rise, at 55C we'll cut the other off as well. As it falls to below 50C, that thermostat should turn it back on. So it will seek around 50-55C on one heater element.

The pump will pump the fluid first through the cabin heat exchanger. This should provide quite a heat drop to warm the large passenger area. The fluid exiting the heat exchanger will be routed to the battery box where it wanders through a series of loops of pex tubing beneath a false aluminum floor in the box. After leaving the box, it will pump back to the fill reservoir.

The glycol should be much cooler on the batteries than on the passenger compartment, but still warm enough to maintain battery temperature.

I know the universal advice is that these batteries need to be cooled. They do not. They do not under any imaginable load cycle. Instead, what we've found is pronounced improvement in all parameters up around 35-40C. Worse, what we've found is pronounced decrease in both capacity and power at anything below 0C. In fact, it has become evident you should not charge these cells AT ALL below freezing.

And so we are going to heat them. We're also going to heat them in the garage while charging, but with a much lower power 240vac heating pad that we will probably affix to the fill reservoir. This won't do much really. But it will be in a garage when we are charging. And it will go on all night. We think a couple hundred watts will very gradually heat the battery box. The side effect will be a warm cabin on entry in the morning.

The vehicle features a remote door lock and even a remote starting system. We're hoping to retain that functionality. Of course, there isn't much to remote start with an electric car, but if it can get the air conditioning or heating going, that would be cool - or....err.... warm.

We used a Ferraz Shawmut A50QS-1200-4 fuse. This monster is the size of a large orange juice can and costs about $350. Sizing these is a pain, and explaining them, even more so. They are a FAST blowing fuse - that blows slowly. No, this makes no sense at all. Neither does the application guide from Ferraz Shawmutt, at least to me. Basically, this fuse will do 2500 amps for about 18 seconds and 4000 amps for 2 seconds. 1200 amps it will do continuously. This does not sound very "fast" to me. I have contacted one of their applications engineers seeking adult supervision on how to size these and how to explain this. So far, no help.

We're mostly using Champlain Cable COmpany's 4/0 shielded cable on this build. This is 4/-0 of copper wrapped in the using poly insulation, then a steal braid, and finally another layer of insulation. I like this for a couple of reasons. The obvious is the decrease in radiated emissions and noise that can affect other components. We do not have the EMI requirements of Europe, but on the other hand banging 2000 amps of 192volts of energy at 8 kHz is going to put out some stuff. One less thing.

Secretly, the reason I would pay $12 per foot for it is that with the layer of steel braid and another layer of insulation, this cable is much more resistant to abrasion. It's going to be very difficult for it to rub through to the copper and connect with frame. It is surprisingly flexible for what it is.

The Solitons already have TWO contractors in each of them. But I caught Sebastien Bourgouis with another pair in his 911 at EVCCON 2011. When asked, he noted it was just redundancy. Ok. Me too then.

And here's why. With other controllers we do usually have a contactor, but we also have a hand switch in the passenger compartment to break the connection to the controllers manually if necessary. I haven't really worked out a way to do that in the Cadillac cockpit. There is this enormous center console between me and the passenger, and no floor space or bulkhead I could conceivably reach.

I'm really NOT a safety Nazi. Prudence is good. But pontificating about safety is not really my thing and some of the extremes espoused by the wannabe experts and poseurs just seem over the top to me. But we have a failure mode with DC motors that is sufficiently rare to be hardly mentioned, but sufficiently possible to pose a danger. And the danger is kind of frightening.

IGBT's can fail SHORTED. Most of the time they just burn up and are destroyed. But it IS possible, though very rare, for them to fail in a short. In the case of a PWM controller feeding a DC eeries motor, this is like connecting the battery pack directly to the motor. With our motors, and this battery pack, that could be 2000 or even 3000 amps OR MORE. When you break an arc at a voltage of 150 and that kind of current, it tends to vaporize metal, and arc weld contactor contacts. Frankly, our manual switch could well be useless too. And that gives rise not to a sunburn, but a vehicle screaming to go at top speed with 300 or 400 kw of power. Not an attractive spectacle for me.

By adding a second set of heavy contractors, using hydrogen dielectric and magnetic blowouts, IN SERIES with the ones in the Solitons, things are maybe better. The arc welded contacts of one contactor set will not really carry current as well as clean contacts and the immediate, almost simultaneous breaking of a second set stand a good chance of breaking that current flow. And if not, the heat generated in the contractors will within a few seconds cause them to go hand grenade anyway.

So that's the theory. We are using two 500A EV-250 kilovacs each capable of breaking 2500 amps. This in addition to the little EV200's in the SOlitons. We'll connect the 12v actuating signal through a big red slap switch on the panel beneath the steering column. I won't have to bumble or look. It's the only switch there, and all you have to do is hit it to disconnect the 12v from the contractors.

We are using TWO Megapacs on the Escalade at 15v. And in addition to our diodes, we are going to add Jeffery Jenkins recommendation of a 100 uh 14 amp inductor to the input to each, along with a 30 amp high voltage fuse.

So that's what we did this week. This is an enjoyable part of a build. The big stuff that takes weeks is over. Now we see progress every day. Little wiring things are fun for me.

Yes I'll try to schedule a private class for Brian on wireless microphone batteries sometime this week if I can find time.


Jack RIckard