Tuesday, May 31, 2011

Let the Voting Begin

This may indeed be our longest show ever - right at three hours of HD video. We had a number of interesting developments and breakdowns in the shop, and then we introduce the TEN finalists in the EVTV "Build Your Dream" EV components contest.

Each of the sponsors selected two of the 955 entries received, and I selected two as well. In itself, that you had a one in a thousand chance at $20,000 in EV stuff is kind of a remarkable thing. You won't find that often or everywhere.

In this episode, we attempted to summarize all of them with a "reading" of their entry and a bit of discussion as to why the sponsor may have found that an attractive notion.

In any event, we will running the balloting from now until August 31, 2011 and each of our viewers will have a chance to make a selection. Help me by making your best considered decision as to where to ship this pile of EV components to have maximum effect. You may vote HERE.

We are designing a drive train for the Aptima Motors eCobra. As a bit of an add-on, Paul at Aptima wanted a J1772 charge station like our Texaco gas pump. I completed that work this week. Paul selected a Chevrolet Corvette pump style and we've been wiring it for J1772 charging. We show the result in this episode.

I have often said I've never met a connector that I liked. I may have finally met my match. The Yazaki J1772 connector has much to recommend it. We are gradually converting all of our cars to work with this connector, and I have gas pumps at the shop and at home. The one at home does not yet feature the J1772 connector, but it will soon. I have fallen in love with them.

Why? They have a very solid feel. You can insert them VERY easily and they lock securely in place with a faint "schnick" as the switch locks in place. We have long eschewed the proper 240 amp connectors on our cars because of the desire to be compatible with 120vac opportunity charging at grandma's house. So we've used Marinco marine covered NEMA 5-15 connectors. They hold up pretty well, but many of our extension cords do not. Over time they become loose and are a bit flimsy. QUITE a bit flimsy compared to the solid cast plastic J1772 connectors.

We had previously published a diagram of how you could wire your car to accept a J1772 charge using a switch, a diode, and about two resistors.

I've recently received a number of e-mail questions seeking this information. We now have an index thanks to Christopher Fischer, but it seems a large percentage of our viewership would expect me to know precisely what episode and minute any particular discussion could be found. Google has indeed spoiled us.

The communications between the J1772 Electric Vehicle Support Equipment (EVSE - we call it a gas pump) and the car is really very simple. The EVSE generates a 12v square wave alternating between +12v and -12vdc and applies it to pin 4 of the connector via a 1 kilohm resistor (1000 ohms). The junction of pin 4 (copilot) and the 1k resistor is then monitored to determine its voltage level.

The duty cycle of this square wave indicates how much current the EVSE is able to supply. The charger in the car is then supposed to limit itself to that amount of current. We don't know of any available charger that can do this. As the nature of such specifications are, we would expect this to be ignored for several years, and at some point in the future, someone will "discover" this feature and use it to communicate something else. It is possible the OEM cars actually look for this waveform, but we would be astounded.

Why? Onboard chargers are rarely of a capacity above 3000 or 3600 watts. They just become to physically large and too physically heavy to fit in a car at much above that. You might see a few 5000 watt units in some select vehicles.

The EVSE seems to have broken into two levels of Level II charging - 32 amp and 70 amp. The first is 7640 watts more or less and the second is 16800. Almost everyone is opting for 70 amp cables and connectors. Either way, its much more power than the car can use in almost every case. And so the recognition of available power is rather moot. And will likely become more so in the future until Level III DC charging becomes a thing.

So the "spoof" we've come up with on the car side is simply a diode, to eliminate the negative portion of the waveform, and two resistors that tie back to the neutral pin of the dual phase supply. This supply, identical to your home 240vac of course, consists of two phase lines of 120vac each, and a neutral return which is tied directly to ground in your electrical panel.

When you plug in the car, the diode and first resistor form a voltage divider with the resistor in the EVSE. It is designed to drop the positive portion of the waveform to +9v. The EVSE would detect this as a "vehicle present" signal. When you throw the switch to engage the other resistor in parallel, this drops the vehicle side resistance to about 877 ohms and the voltage to about +6v signaling the EVSE to provide power. There is another level lower yet for signalling for ventilation. This would be for flooded lead acid batteries that produce hydrogen when charging. We don't expect that to be used at all.

We rather thought someone would develop a little PCB to implement all this on the EVSE side quite properly. David Kerzel threatened to, but never completed the project. And someone should. One viewer sent us a device from Menneckes that purported to do that. It was quite complicated and limited to 32 amps. And it's somewhat expensive.

So we genned up a horribly simple little spoof circuit to accomplish basically the same thing, but without the square wave. It just uses a simple 12v to energize two Kilovac ANA200 contactors. Each contactor carries a single phase of the power. And so when they are NOT energized, there is NO power in the cable at all beyond the 12v signaling voltage which is provided by a 3 amp 12v supply inside the pump that feeds off a single phase of the input power.

The circuit is shown below.

This circuit is so blatantly simplified and NOT SAE J1772 2010 that I refer to it as J1771 1/2. The entire circuit is mounted on a 1 inch square of PCBoard material. The heart of it is an LM1458 operational amplifier we use as comparator. 12v is applied across a 5k potentiometer to ground. The wiper is adjusted for 6v and applied to the + (non inverting) input of the opamp. The same 12v is applied across a 1k resistor to the - or inverting input. The junction of the 1k resistor and the opamp input is tied to pin 4 of the J1772 connector - the copilot signal.

The output of the opamp switches a fairly sturdy MOSFET which is connected in series with the coil of a small relay. When energized, the relay switches 12v to the two phase contactors, energizing them to apply power to the car. It is somewhat important to tie the neutral pin of J1772 to the common or ground side of the 12v power supply.

In this way, the switch on the car, when closed, drops the voltage to 6v, the comparator output goes positive, the MOSFET turns on, and the relay switches on the contactors. We simply adjust the pot to trip at that point.

So we wind up with much of the safety and sturdiness of the J1772 spec, without the complexity. Eventually, someone WILL do a proper circuit for this with ground fault sensing. Better, use GFI circuit breakers in the panel.

A team of five or six engineering students from Imperial College in London, devised a plan to build an electric car and drive 26,000 kilometers down the Pan American highway from Anchorage Alaska to Urushaia at the southern tip of South America. They filmed this journey and we had ordered a copy when they completed the thing last November. We received it just last week and had actually forgotten we had ordered it as it was six months late in arriving. http://www.racinggreenendurance.com

The thing winds up as eight episodes on two DVD's. It's 19.99 British Pounds so about $30 before shipping but you have to see this. It is too comical to believe.

First, they built an open top SRO race car with a massive 50kw Thundersky battery pack and a 3.5 inch ground clearance to drive across the Pan American highway. Idiotic in concept from the get go. The tiny racing shock absorbers were sporting 1100 additional pounds of batteries. Engineering school apparently isn't what it once was.

But their "mission" was to drive from one press event to another, touting how electric cars were finally here and practical for every day driving. Instead, they rather proved both graphically and dramatically that it takes a half a dozen recent engineering school grads to even keep an electric car rolling at all.

Never at any point in the journey did they pick up on the irony. They wrecked the car twice. It burst into flames several times. And they failed every piece of equipment in the car with the exception of the very sexy EVO motors they had. All four shock absorbers broke at various times in the journey. They burned up their chargers. They burned up their BMS quite frightfully and the DC-DC converter at one point. Almost everything we've ever destroyed here in the shop, they managed to tick off the list on the road. No matter how rain bedraggled and discouraged, there they would be at the next press event with the canned speech about how great the electric car was and how well adapted it was to all of this. I watched every minute enthralled.

They never really went into any useful detail on all these failures during the whole series. They would show some discouragement, vaguely describe what they think happened, and then seek the assistance of some Mexican or South American farmer to make the repairs.

One of things I did pick up very early in the first episode was that they used a pair of Rinehart Motion Systems PMX100 controllers to drive the pair of EVO motors, which were direct drive to each rear wheel. And they complained of severe Electro Magnetic Interference (EMI) problems which they initially solved by wrapping the UVW phase cables from the controller to the motor in aluminum foil. Eventually, they replaced the foil with shielded cable.

We had been suffering for months with some gnawing problems with the Mini Cooper. I drive it every day. But there is always a slight shudder on takeoff at low RPMS. Worse, Rinehart has finally implemented a proper brake potentiometer input to control regenerative braking. We use a hydraulic pressure transducer to produce this 0-5v signal and it appears to work quite well. But whenever we had it CONNECTED to the controller, whether using this braking mode or not, we get an over current or over voltage fault at about 3500 rpm and the controller shuts down. So we are stuck with brake light signal regen and have to leave the transducer disconnected to drive the car.

We had actually sent Rinehart one of these transducers. Their car ran fine and they were unable to reproduce the faults. Very puzzling.

After watching the episode, I somewhat loosely wrapped the phase cables in aluminum foil and tied them to ground. The faults disappeared and the shudder as well. Elated, I had Karl remove the aluminum foil and install some braided steel tubing over the cables. To do so, he had to disconnect the cables from the controller.

Each cable was terminated in a ferrule crimped around the strands of the cable and then this is locked in place with some hex bolts in the controller. Unfortunately, when you lock them in, it deforms the ferrule. When you disconnect them, the cable then comes out but the ferrule does not.

To reassemble, he simply stuck the cable back in and tightened it down. But the old ferrules were in the controller. And a strand of the center cable made ground. When we applied power, we blew up the controller.

While this is discouraging, everyone is a bit elated. Rinehart is happy to repair it, and we're happy to send it off, because this nagging question seems to be solved.

The actual solution is of course the shielded high voltage cable. Unfortunately, this is horrendously expensive. But we think EMI may be the cause of a lot of things - like blown DC-DC converters, instrumentation ghosts, etc. It is particuarlly an issue with AC systems. But we are going to start using this cable anyway on ALL installations. Both battery and motor connections. It is manufactured by Champlain Cable Corporation EXRAD XLX shielded cable specifically for electric and hybrid vehicles. And basically after THIS months long drama, we are simply going to the use of that for everything regardless of expense.

Per usual, Chris Brune of Rinehart Motion Systems had brought up "noise" several times as a cause. He was sufficiently vague about it that I bullheadedly dismissed it each time. Just shoot me. Again, the main value YOU derive from these videos is from me screwing things up - AGAIN. I have on NUMEROUS occasions mentioned the EMI problem, particularly with regards to delicate BMS and instrumentation circuitry. I probably need to watch my own videos a bit. Too soon old. Too late smart. Spend the money on shielded cable and it won't be a problem. No more welding cable at EVTV.

We received our Tremec TKO600 transmission from Mike Fortes of Fortes Parts Connection this week, along with a Ram 11 inch ceramic clutch and pressure plate, a lightweight aluminum flywheel with steel face plate insert, and hydraulic clutch slave cylinder. Mike has a lot of Cobra experience and has provided some serious adult supervision here on components for the Aptima Motors drive train. This tranny/clutch should handle up to 600 ft-lbs of torque on the eCobra.

Matt Hauber has returned to San Diego to begin his life as electric vehicle converter extraordinaire. I understand he's starting out with an S10 pickup conversion there. He was a very talented and useful young man here at EVTV. His youthful enthusiasm made us all edgy. Or maybe envious. I'm uncertain which.

We welcome Carl Skircheck to the team. Carl actually had an early career in race cars in Detroit where he grew up and has managed a Chrysler parts department in recent years. Much of the mechanicals we find mysterious here at EVTV seem to come easily to Carl. With a couple of phone calls he has located some Silicon Oxide ceramic bearings for Speedster Part Duh which we are going to try. He is going to mount the Tremec in the Cobra this next week. He immediately brings to mind how embarassingly little Brain and I really know about automobiles and particuarly parts and mechanical assemblies. This may make the 3 lbs hammer entirely unnecessary here at the Motor Verks.

Jack RIckard

Tuesday, May 24, 2011

Of Kits and Cars at Carlisle

This week we are a bit late with the show. Worse, our audio is a mess. We've never mastered the wind with our little wireless microphones. It won't sound like the wind to you of course. More like a freight train as it is amplified several dB. But we have it up to view.

So what's with kit cars and electric cars?

We were the only electrics at the event. I expected some horseplay from the petrol inebriated at this event, particularly because it tends to be a historic reflection on automobiles. This year's "theme" was French cars and almost entirely French vintage cars of course. But there were some fabulous displays of old Saab's and Volvos etc. I fell in love with a 1960 Saab 95 in a kind of dusky green color. Very peculiar looking little car.

With all that history, you would think we would draw some frowns with our newly contrived electric drive Porsche replicas. Not the case. Everyone was thoroughly interested and quite polite about it, a lot of very pertinent questions and they correctly went straight to the battery chemistry at the heart of it.

The Speedster Owners group from www.speedsterowners.com was in strong attendance this year - probably 80 people many with cars. A few Spyders among them. On Thursday night, we went on a "cruise" with this group and wound up eating at the Caddy Shack, a local golf course restuarant with really quite exceptional food. Vert friendly group of people who very nicely included us in their activities.

This group is kind of an oddity online. If you go to www.speedsterowners.com you will notice something very peculiar about their forums. They are kind of boring. The reason they are kind of boring is that they have a culture of being nice to each other online and there are none of the flamewars that seem almost a requirement for an online forum.

The reason there are none of the flamewars, and everybody is busy being nice to each other, is that they actually MEET in person at Carlisle and Morrow Bay and a couple of other venues about the country. Having met face to face, or perhaps about to, has a very subtle but strong effect on their online interactions. I have hopes we can recreate this type of online forum augmentation with our Electric Vehicle Conversion Convention (EVCCON) scheduled for later this year in September. My hope is that by actually meeting in person, they will then strive to simulate actual humanoids in the online forums.

We were gratified to see so many of our viewers at Carlisle. I thought this quite coincidental, until a couple of them told me they came to Carlisle specifically to see us. Perhaps we've missed a trick. We need to get out more.

I dislike travel intensely, which you will find a little odd in a guy with eight or ten airplanes in a hangar at the airport. But it is true. Everything becomes a task. A glass of tea is a project. A trip to the toilet becomes a journey to mecca. A cup of coffee takes group collaboration.

I guess the overall impression I had of the show was of a long enduring mature industry, suffering from having victimized itself over the years to the point of almost irrelevancy. There have been so many crooks in the kit car business it makes honest men look a little smarmy just by being among them. And the overriding theme seems to be to find someone who succeeds with something, and immediately copy it both badly and cheaply. Their belief system in stealing concepts and innovations from each other is deeply ingrained. The majority of them think it's a good thing.

The contrast was interesting in places. We of course visited with Kevin and Carie Hines of Special Editions Inc and they were there in force with a Speedster, a Spyder, and their new Porsche 904 on display. I always struggle to describe these guys. They are Special Editions Inc., but they are also Beck Speedster, Beck Spyder, and Beck Porsche 904. Chuck Beck is a half century one man industry of innovation and entreprenurial activity and kinda/sorta partner in all this - I've never quite worked it all out. But they are careful to GIVE him credit for their cars. I gather Chuck doesn't really enjoy the day to day grind of manufacture and dealing with customers. But their relationship has spanned many years.

Almost directly across from them was JP Motorsports. This guy generally finds an idea and copies it cheaply. I did introduce myself and he immediately explained to me that they had built the ULTIMATE electric car already using the best of everything and it was nothing but a golf cart and a joke. No doubt. He then ordered Brian to stay away from the cars and not look at them. What he was doing at a car show I cannot imagine, but the purpose he served best was to exemplify what being a bitter and hateful little man is all about when bringing this to the level of art form. It was so bad I thought he was kidding at first, kind of a Don Rickles routine. So I started to play along. If anyone knows how to BE an asshole, it would be yours truly. I've certain genetic advantages anyway and then of course there is the careful honing and study of the art over decades. But it appears he prefers to dish it out and is not very good at doing it as a back and forth banter type of gig.

Bruce Meyers was there. A kind of aging giant of the industry, he invented the Meyers Manx, a truly artistic and very avante garde departure in the 1960's. You may know it better as a "dune buggy". Even then, he had hardly sold a dozen when a fiberglass shower stall manufacturer down the street bought one of his creations and brazenly did a mold from it. Fifty years later, he is still visibly bitter about it. He actually left the industry for many years but this year he is back with a whole new line of these things and they were very attractive.

t was at Pismo Beach, CA that Bruce first became acquainted with "dune buggies". These "water pumpers" were crude and heavy so Bruce took it upon himself to design a lightweight version that would be fun on the beach or in the wilds of Baja. After modifying a VW Kombi bus with wide rims (called "Little Red Riding Bus"), Bruce used his expertise in boat building to design the first fiberglass-bodied dune buggy, the Meyers Manx.

The first 12 cars produced were all-fiberglass, monocoque bodies that had a steel structural frame within the fiberglass that attached to the VW suspension and running gear (“Old Red” - #1 now resides with Bruce). These cars were expensive (for their time) and redundant in that so much of the VW was thrown away. Bruce redesigned the body to fit on a shortened VW floorpan, which ultimately reduced the price as well. As a result, the Meyers Manx took off. It took the country by storm when magazines like Hot Rod and Car & Driver featured the fiberglass car on their covers. This caused a rash of over 300 orders. Not able to immediately fill these orders, other manufacturers sprang up overnight and ended up producing over 250,000 look-a-likes and near look-a-likes. Eventually over 300 companies, worldwide, copied the Manx in one form or another – even the copiers copied each other. Bruce tried to stop the floodgate of imitations with patent infringement laws but failed to convince the judge that he had produced anything worth a patent. In subsequent years B.F. Meyers & Co. built 5,280 Manx kits, several hundred Manx 2's, about 1,000 Meyers Tow’ds, a couple of hundred Manx SR’s and 75 Resorters - a total of nearly 7,000 kits.

Meyers closed the company in 1971, having spawned a mini-industry of copies that has gone on for nearly half a century.

Today, he is back in production with several attractive versions. We found the Kickout SS very intriguing.
Meyers Manx

Bruce has been contacted by the California CARB about doing an electric version of the vehicle and we discussed this with him a bit while we were out there.

And that appears to be the theme. Kit Cars provide a good platform for those building their own cars. They have none of the CANBUS/OBDII/ECU issues of a new modern car. They tend to be a bit spartan on creature comforts, but they are simple cars at reasonable prices. GENERALLY they are available as rollers if you don't want to do the kit build yourself, but are often available at several levels of completion. You wind up with a NEW car and don't have to face the rust and restoration issues of bringing a genuine classic back from the dead. And so we are seeing a lot of excellent builds coming from the kit car end of the spectrum.

We found another bit of interest at the show. The Autocross. The electric autocross is nothing new, but they tend to be a cone works in a really ugly back parking lot somewhere. At Carlisle, they have a beautiful little track for this and there is an elevated embankment to view it from. They dropped the ball quite horribly on it. There was no "leader board" announcer, or even an LED clock showing the last time run. But it was still fun to watch.

So much so, that I've asked Brain to make it so at EVCCON. We have an airport. But I want each car and driver announced over the public address, a clock showing the time as it runs, and a leader board showing who did what. I'm thinking this can be the Friday evening activity.

We did an interesting experiment with this. Brain took the powerful Speedster Redux on three runs of three laps each. Best time for this 156HP vehicle at 2385 lbs was 32.6 seconds. Next he did the Spyder. Right at 2000 lbs and 76HP. Best time, 29.4 seconds. That's over 3 seconds difference or 10%. And it proves a point that Porsche actually made with the Spyder in 1955. Lighter weight and lower power will beat heavier cars with more power on a track = essentially 100% of the time. The only time the Spyder lost that season was when it didn't finish due to mechanical difficulties.

A pound is a pound is a pound and worse for electric vehicle designers, it is a permanent pound forever. If you design it in, it will be with the car on every trip henceforth, and will effect each and every single application of the throttle from thence forward. It is cruelly omnipresent. A pound is forever.

I've spent the last six months hearing about how much more powerful the Speedster Redux is. I don't race, but I have on almost all occasions mentioned to these guys that somehow the Speedster Duh just "feels" better to me. The ivory car picked up a seal leak from the right transaxle on the truck trip out, and we feared to put it in the autocross as the transaxle fluid was very low. That would have been interesting.

I don't really have a "range requirement". OF course, range is a defining issue in the talk about electric cars and so the "bragging rights" of a 150 mile Speedster are of note. But truly in designing a car, you simply do NOT want to design in a pound you don't need, and that means a RANGE you don't need either. I don't really have a commute (ok, a block and a half) but my "use" for a Speedster is to take it out on the backcountry blacktop winding hilly roads we have so plentifully here in Southeast Missouri. You can go from about 40 up to 65 in places and you tend to vary wildly between those speeds. It will do that for two and half hours, which is about a half hour longer than I will. It is fun, but not so comfortable that I would ever do it for 3 hours.

And so the 2039 lb Speedster Duh feels right to me and is not overdesigned for range. Since it exceeds the performance of the 1957 Porsche Speedster in all respects anyway, I'm guessing it's good enough for the job now. And it is truly fun to drive. We CAN make it more powerful. And we CAN make it go further. That's not to say we should.

Something to think about with your conversion. What do you REALLY want it to do.

ME? I want an aluminum chassis, aluminum rotors, and a carbon fiber body. We'll use LESS power and LESS batteries with that. Sometimes more is just more....

Jack Rickard

Sunday, May 15, 2011

Electric Cadillac Elescalade Progress

We're finally making a bit of progress on the Cadillac Elescalade Project.

Lucien completed our auxiliary adapter plate for the 11 inch motors. This is our enormous polish friend from Cape Precision Machine. They have taken a good bit of time with this project, but it's true I had told them there was no rush as we are waiting on batteries. In any event, the final product seems worth the wait.

This is a 7/8 inch adapter plate of 6061 aluminum. It is recessed both to accept the boss on the face of the motor, and the motor itself and so you can tap it on with a hammer and it probably wouldn't even need screws. We do have eight flathead allen screws that secure it.

This plate provides mounting for our Air Conditioning Compressor and the Power Steering Pump. We put in an idler from the Cadllac, a tensioner from the Cadlilac and in fact used a Cadlllac Power Steering Pump pulley as the drive pulley.

The drive pulley was the key. They had to hog out the existing diameter on this and put in a new bushing, properly centered, to fit the 7/8 inch auxilliary shaft of the motor. But wait! There's more!

We want to use the Engine Control Unit (ECU) on the vehicle. This little computer gets inputs from all over the car, but by far and away the most important is engine RPM. Without the RPM signal, it thinks the engine is stopped.
Acutally it is GONE entirely but we want it to think our electric motor is somehow an ICE engine.

So we were able to order what is termed a RELUCTOR RING from GM that normally resides on the crankshaft of the L2 engine. A small pickup unit then is threaded into the block to pick up a series of pulses from the teeth of this ring.

We dont' have a block. We don't have a crankshaft. So we mounted this ring on the drive pulley. We'll then mount the pickup on the adapter plate and hopefully provide the ECU with accurate RPM information in a format it likes.

The plate also provides mounting for a couple of aluminum billet brackets to properly locate the air conditioning compressor and power steering pump. To change these, we'll simply unbolt the normal mounting bolts and pull straight up. They come right out.

The Power Steering pump is actually part of a larger project. We are going to replace the vacuum assited brakes with brakes using a unit GM calls "hydroboost". These are often used on diesels who do not generate sufficient vacuuum pressure. They work off hydraulic pressure from the power steering pump, which then powers both steering and brakes.

One of the hangups was using a stock belt. I kind of insisted on this. Lay it out however you want, but use a stock 6 rib serpentine belt I can buy at NAPA. This way, if we lose a belt, we can obtain a normal NAPA part number belt off the rack. The result was 71 1/8 inches of belt. We had them scribe the part number INTO the adapter plate. 12 years from now when this is an issue, I can write down this number, go to NAPA, and hopefully they can make me well.

The unit ran totally silently, with no wobbles or vibrations at all. This is the kind of thing where you can save a few bucks on a conversion by doing it yourself, and most people doing a car will do this. I can't fault it, but for me, it's kind of important to get this part right. And we've had some adventures with the mechanix of these things anyway on the Mini Cooper.

In this episode, we also tackle the battery box. We've centered on a main pack of 57 Winston Battery COmpany 400 AH LiFeYPo4 cells. I started with Thunderskys's, went to Sky Energy, and now back to the yellow batteries. Why? I like the flatter discharge curve of the CALBs. But I had not had cells from TS since the addition of the Yttrium to the cathode material. This appears to lengthen the life and in fact, they are claiming 5000 cycles at 70% discharge.

Ultimately, beyond power, beyond energy density, I am about cell life. I actually think we may have accidentally stumbled onto something with the Chinese battery suppliers putting us at an advantage over the Panasonic's and LG Chems favored by the OEM auto makers. Yes, we forfeit a bit of energy density, though precious little. In return we get a hardy package, and cell life. The Panasonics used by Tesla appear to be rated for 300 cycles. We have a "secrete" internal memorandum with page after page of concerns over this, so I'm not alone in this, plenty within Tesla are concerned as well. We actually picked up an interesting thing from this document. Apparently, the Panasonics lose 20% of their capacity per year just sitting - if fully charged. If discharged to 50% SOC, this deterioration drops to 4%.

This is in line with our belief system about keeping the cells as close to 50% as possible for long life. But how do you keep a cell at 50% when you're driving the car. The natural propensity is to fully charge it. That way its ready if you need it. But apparently the batteries would last longer if you would NOT park it for days on end at full charge.

I dont' think we have a 20% capacity decrease per year. But we probably have some, and this more or less holds true four our cells as well, just probably to a much lesser degree, and perhaps to a degree where it doesn't really matter.

In any event, the 3000/5000 cycles in the Winston Battery Company cells appear to be the top of the mark. And up from the 2000/3000 cycles prior to the Yttrium rare earth additive. So we wanted to try them.

400 AH cells will be the largest we've done and in fact the largest we've seen done in a passenger vehicle. These cells are fully 18 inches wide, though their height and thickness are quite familiar from the 160 AH models.

We think we can do three rows of 19 cells in a package 50x56 inches. That's 1696 lbs of cells in a 3/4 ton pickup truck. And it will give us 191 volts at 400 AH for 76380 watt-hours of energy. I'm looking for the truck to come in about 7500 lbs in the end, which should indicate about 750 wH per mile. I don't know if we will gain efficiency or lose it in going to this size, but I would be willing to guess that the wH/mile could be almost anything BUT 750wH/m therefore.

In any event, that sounds like 100 mile max range, 80 mile safe range. Familiar. No matter what size vehicle we do, that's about what it comes out to.

I actually have 70 cells coming. We may do some further packs under neath the frame. That would take us to 93800 or about 115 miles perhaps max range.

We have two Soliton 1 controllers each capable of 1000 Amps and we want none less from this pair. 2000 amperes of power. But in truth, this would normally be for a second or two. That would be 5C for these cells. well within their capability. Recall that we did simliar testing in REDUX Speedster at about 5.5C and the CALB cells worked marvelously. So despite two eleven inch motors and two Soliton controllers, I expect these much larger 400Ah cells to be loafing most of the time.

We have noticed sluggish batteries in the dead cold of winter - easily 15% degradation. Given the expense of this pack and it's size, we've decided to make provisions to heat them.

And so a special battery box with a false floor and PEX 180degree Fahrenheit tubing in the bottom. We'll heat glycol and water and use it to heat ourselves first, and our batteries in the rear. We're also going to add an AC pump and block heater to gently heat them while charging overnight.

Enjoy the video.

Jack Rickard

Wednesday, May 11, 2011

The EVTV Conversion Shop - We Don't Do Requests.

Wayne Alexander has probably the most ACTIVE EV conversion shop in all Christendom with EVBlue.  Wayne's philosophy is "give the customer what he wants".

I'm a little bit of a crank I suppose.  Were I to do a conversion shop, it would be more like "give the customer what you want them to have."

We've had a bit of an epiphany here at EVTV largely deriving from the massive 598 page contest document we still wrestle with rather actively.  I'm anxious to announce the 10 finalists, but our sponsors are similarly finding their choices difficult.  Among the 955 entries, after all the winnowing in the world, there are a number of really good ones.

A common theme running through it is the largish percentage who don't precisely want to build an electric car.  They want to build an electric car, and then ANOTHER electric car, and they want to keep doing that unto their departure from this world.   Some already DO have conversion shops, but it is clear there is a huge desire to do that.

My original interest was batteries, and video.  We propose to be the definitive niche video show for the genre.  I am not myself attracted to the idea of an automobile manufactory.  But I get it.  Now what to do about it.

If that IS the dream of a significant percentage or our viewers, we should be knowledgeable on the topic - what works, what doesn't, what to do, what to avoid.  We can do some of that vicariously, and intend to.

But our concept of "journalism" varies somewhat from the norm.  We believe you publish best with a thorough and rigorous knowledge of the topic, and frankly we openly deride the chippy journalism taught in media school about how to ask incisive questions.  To my way of thinking, if you purport to report on a topic, you should know it thoroughly.  And of course, you learn by doing.

So how to simulate a conversion shop while not doing any of that?  An unsolvable puzzle, my favorite kind.

We were approached kind of separately by a Taiwanese electric railroad executive and a Kit Car manufacturer from the far southwest corner of Missouri with some apparently random questions all centering on the same car - the Shelby Cobra.

I have too main interests in cars - enormous land yachts and tiny sports cars.  The "muscle" car thing never quite worked for me.  But I will admit the Cobra is  a bit attractive and to some degree unique.  Kind of "sport car" sized but with a honkin big 429 V8 in it.  Kind of like putting a $10,000 hand tooled saddle on a $200 mule.  I like V12 engines.  I like MG's.   Never occurred to me to PUT a V12 IN an MG, but out of the box thinking is always attractive to me.

Now an ELECTRIC Cobra?  And as I say, kind of a random thing.  How do you put a VW transaxle in a Cobra?  Could it be done with SLI batteries from WalMart?  etc.

As it turns out, the two separate streams of questions were really one.  A gentleman from Taiwan who wants to develop an electric Cobra for sale in China, and a 30 year veteran kit car builder from Missouri who, like Wayne Alexander, wants to give the customer "what he wants".

At some point, somebody has to design something on purpose.  A collaboration where the builder picks one part, and the customer picks a second, and they continue like choosing up sides for a neighborhood baseball team, does not, to my eye, look like a formula for success.

I like a model where the customer defines the REQUIREMENTS ( goes 171.5 mph, accelerates 0-60 in 3.5 days, range of 22,000 telephone poles, etc), and the builder indicates expensive areas (171.5 mph) and areas that could easily be improved (0-60 in 2.2 days) and things that are in the category "are you sure" like 22000 telephone poles per hour.

Once that is all layed out, I would advocate you give the customer what you want him to have. Someone has to select components with a knowledge of:

1. What's available.  You may have info on new products that just haven't migrated to the body politic.

2.  What's affordable - sure, a $34,000 UQM AC drive train is perhaps nice (haven't ever used one frankly) but how nice is it at seven times the price?

3. What works well TOGETHER.  Random components do not a car make.

4. What works for THIS particular car choice.  These kind of cars have a history, a culture, and an expectation set built in.  If you are going to convert it to electric, you are already throwing the baby out with the bathwater.  But what holy icons do you NOT want to disturb.

And from there you move onto finer points like how much trouble it is to assemble, what would be like to MAINTAIN, what would it be like to maintain say at a distance of 8000 miles and across a couple of language barriers, etc.  If it takes a day and a lift to take some voltage measurements, probably not a good thing.

In any event, my first reaction was to send these guys back into the amorphous Internet from whence they came.  Oddly both persisted in some sincerety that they really wanted to do this car and wanted an excellent electric car to be the outcome.   So I took a closer look at the AC Cobra as a platform.

What I found was indeed a vehicle with a following.  It's one of the most popular kit cars on the ground with numerous small firms producing these vehicles.  Typically with a comically over strong Ford 9-inch rear end, a T5 five speed transmission, and almost always a V8, choice of small block or heavy breather, big tires, enormous side exhaust pipes.

But often not weighing a lot more than our Speedsters.  LOTs of legroom.  And kind of a huge amount of space for batteries.  The flanks of this beast have those sensuous feminine curves I confess I have a weakness for (Speedster, Spyder, MG).  And then kind of a raw quirky WWII aircraft dash board with a speedometer that turns BACKWARDS.

Hmmm.  And the gentleman had aspirations to sell these in modest quantities in China under the name Aptima Motors.   Hmmm....  I was gradually developing an attachment to the vision.

So I told them to send me the car.  We'd make it an EVTV project.  And build the best one we knew how.  I can't tell them what will go in it because I don't know yet.  I spend a lot of time with a measuring stick and a cellphone calculator around here already.  And usually if I scratch my ass and pick my nose furiously enough for a few days, we come up with a plan.   So far, they've all worked out surprisingly well.  120 mph range.....  0-60 in 6 to 8 seconds.....  120mph top speed..... that's a bit of a challenge from all directions.  This lazy car is going to want an 80 mile range, a ten second 0-60 and top out at 95 mph.

But the Ford rear end has an endless array of ratios.  There are endless transmission options.  And there's a lot of space when you DON'T have a 429 in it.  And with about 800 LED's in the front scoop it WOULD look a little like a flame thrower.

This week Brian Anderson of B&B Manufacturing  in the greater Granby Missouri metropolitan area  brought his creation, a very unusual "Turnkey Minus" of his Cobra kit car to EVTV.  Brian has built 2500 of these over the past 30 years.  This one is kind of special in that it has been seriously "lightened" to a scant 1360 lbs.  An eggregiously strong X member that is kind of his hallmark on his version of this car has been removed.  And in this week's show Brian gives us a walkaround of the vehicle - our first up-close look.

So we've been scratching and picking ever since.  The vehicle comes with a 3.25 rear end which I'm kind of attracted to.  But we'll probably replace it with limited slip.  We looked at automatic transmissions for this, but we have ordered a Tremec TKO-600 monster from Mike Fortes, who does a lot of tranny's for the Cobra crowd and seemed knowledgeable on the surprisingly large bevy of piece parts and options that you have to deal with with one of these transmissions.  The TKO 600 is nominally a 600 ft-lb transmission.  My sense is we need some power for such a vehicle, and my sense is since I'm sitting next to the transmission, I don't want it to do the Claymore mine simulation when we first apply it.  I admit it may be overkill.  After our recent experience with a 9inch Netgain and a Soliton in Redux, blowing a Stage II Kennedy clutch, I guess I think overkill is appropriate.  We're going to use a hydraulic clutch with an 11 inch disk.

I think one interesting thing we can do with this project is change it from a four wheel car to an eight wheel car.  I'm going to spring for some lightweight narrower wheels and some Michelin Energy savers.  It currently has some very wide, very sticky wheels and tires on it that look very Cobra.  I can only imagine the rolling resistance.  So we are going to have two sets of tires and wheels, and we'll pick out a circuit and demonstrate for you just specifically what difference rolling resistance makes in your energy usage - to several decimal places.

Given the space, I am inclined to attempt a 240 volt pack of 160 or 180 or even 200 AH cells.  I don't have that all quite layed out yet.  But that's a goal.

Beyond that, we're pretty open on a drive train and etcs.  We've kind of had some success in the past with our very knowledgeable viewers bailing me out of assorted mayhem and mistakes.  So before I order a random sampling of parts, this would be a good time to tell me what I SHOULD have done, that is before I do it.

And finally, I have to acknowledge that the somewhat ironic reversal has some appeal.  IT would be kind of an interesting turn if a very small manufacturing company in Southwest Missouri wound up producing electric cars for export to China.  So we want this prototype to be something special.


Jack Rickard

Monday, May 2, 2011

Call it a Week....

This week we round up some various and largely unrelated items for your viewing pleasure. We actually had a number of interesting things planned, and NONE of them really panned out. It was one disaster after another. The result was there really wasn't much to show. Busted....

Thanks to Count Domagni, we did get the new website up and running. It is now hosted entirely on Amazon.com. I'm assured it is graphically more pleasing than my large photograph efforts. But it has not been without problems. And we continue to struggle to work with all browsers and all movie formats. HTML5 was not the panacea expected, and so it is two steps forward and three steps back. We will stay with it. Many thanks for the various problem reports and suggestions.

Recall we had installed a brake transducer in the Mini Cooper. I'm quite enamored of this device and will post the first page of the data sheet here. They are available on DigiKey and they have them in a variety of pressure ranges and a variety of port sizes.

What I like about this device is that it puts out a 0-5v variable output based on brake pedal pressure. Actually, it reacts to changes in brake LINE pressure and of course that is a result of brake pedal pressure of course. It allows you to provide an input to your controller for regenerative braking that is truly representative of your pedal effort, giving a fantastic sense of control of regenerative braking.

The Mini Cooper Clubman has a power assisted braking system. We did NOT want to use a vacuum pump to enable that, and of course we DID want to take advantage of regenerative braking available in our AC induction drive system.

Recall we had replaced our TIMS600 controller, which I blew up, with a Rinehart Motion Systems controller at some additional expense. I have to tell you that I very much LIKE this controller, and cannot at this point recommend its use for any purpose. This thing just isn't done. We're kind of on the beta team.

Their manual had described a 5k potentiometer brake input for regenerative braking. But when we received the controller, we were told that that had not actually been implemented yet. But they planned to.

We have had a number of problems with the Rinehart, most notably a distinct and upsetting "shudder" when you first start in motion. They allude to "driveline resonance" as being the problem. As we had no such "driveline resonance" with the TIMS600 with the same motor, and have not encountered this in two other cars with AC induction drives, I guess I'm a little unconvinced that "its the car's fault." They put an anti-shudder algorithm in which helps, but then IT causes the car to jerk a bit when you are NOT moving.

In any event, they finally implemented the 3 wire input for regen and put in some new variables to set min, max, and change the brake mode.

We had previously helped them develop a braking ramp function based on time. This would cause the brake to initially match the regen level of the accelerator when you're foot was off the throttle, and ramp up to a maximum regen variable you could set. You can also assign a time value to the process. We use about 3 seconds. And so when you step on the brake, the regen linearly increases over the course of 3 seconds. If you start to develop too much braking, simply lift your foot and stab it again to reset the ramp. This brake "pumping" exercise is slightly annoying, but actually works pretty well. It was a huge improvement on what they had, which had been MAXIMUM braking when you first stepped on the pedal and then linearly DECREASING as RPM came down. This made no sense at all and felt terrible.

We wired up the transducer to the new inputs. The results were mixed.

First, the brake transducer regen works and works very well. Much improved brake feel and we can of course tune it further by changing the maximum brake torque and the mapping of the brake pedal input. But it introduced NEW problems. Most notably, at some random point between 3500 and 5000 rpm, the controller shuts down completely. This happens both on acceleration and braking and we could find no pattern other than it occurs somewhere in that rpm range, and so more often in first gear than second.

The more alarming and thoroughly inexplicable problem is that if you put it in electric "reverse" and give it just a touch of throttle, the car BUCKS violently.

Unfortinately, the Rinehart guys were out this week working with a motorcycle racing team and didn't have time to fool with us. This is a bit perplexing as it appears we are fooling around with THEM and spending a lot of time troubleshooting obvious problems that should have already been taken care of. Note that all of these items are NOT precisely configuration that we have not done correctly. Mostly they have involved new software releases to fix the problem. So we're kind of on the beta time with Rinehart.

As I like the physical package, we don't really mind. But it sure busted my program this week when they winked out on me. It takes some time to get set up for these tests and when you are reporting the results and have everything set up to make changes quickly and report back, it is a little disconcerting to get dumped for a better offer. Oh well, we have three guys and they have about that and it is just the nature of this cottage level industry.

We understand they are also working with a guy who has done an implementation of the Remy motor with a case that makes it something you COULD use and solves the cooling issues with this motor. More on that later.

So we think the Rinehart is a comer, but it's not quite ready for prime time yet.

We decided to install the PowerOne Aurora solar inverter in the garage at the house. This is a 6kw unit we showed on an earlier show that has a wide DC input range of 120-530vdc and puts out standard 240vac split phase 60Hz just like your house.

Our garage is separate from the house, but on the same side of the meter. I actually have an AC disconnect switch and natural gas 10kw generator already installed. If we lose grid, the switch disconnects us from the grid, connects us to the generator, and starts the generator. In this way, if they are out working on the grid, we don't light them up.
This is how this has been done for twenty years and it works extremely well. The problem is the switch is $400.

The Aurora is a grid tie inverter, and will match phase with your existing grid input. Any power you make with solar or wind for example, will be used locally and in fact, if it makes more power than you are using, it will run your meter backwards - if you have a meter that the utility hasn't modified to NOT run backwards, meaning you pretty much have to be in a net metering state at this point.

We hooked up the Aurora in kind of a strange configuration. I was going to connect it with a conduit to an existing box in the garage. Matt noted that we could just put a heavy cord on it, and plug it IN to the receptacle, giving us the option of UNPLUGGING it quite easily. I bit on it.

We plugged a cord we were using on a heavy heater into the jack and carefully measured the distance to the connectors in the Aurora. Matt then cut the cable with a large set of thankfully insulated cable cutters.

Unfortunately, we still had the cable plugged IN to the wall. We lose more interns this way. We included a little bit of video illustrating this event in today's show. Don't try this at home.

We did hook up the Mini Cooper to the inverter, and in fact it DID make power. Quite well actually. It was a tad over 6kw and in comparing the voltage and current IN to what it was reporting as output, this is a VERY efficient inverter, and totally silent. Good equipment.

Unfortunately, it won't work by itself as a backup power unit. Apparently, along the way, the power companies have caused some UL codes to be implemented that REQUIRES grid power for this device to operate at all. If you lose grid power, it shuts down as well. This "anti-islanding feature is ostensibly to prevent putting power out on the grid endangering the utility workers that might be working on the system.

What it really does is prevent you from using your solar or wind to backup your grid connection. I guess it eliminates the need for the $400 switch, but I smell an untold story of conspiracy and greed.

I went through every single inverter manufacturer I could find, and found a curious thing. They ALL had implemented this, and are apparently required to.

What about OFF grid inverters. Curiously, there aren't many of them anymore. But there are a few. Outback still makes some. But curiously THEY are ALL limited to single phase 120vac. There are no 240vac off grid inverters I could find. Curiouser and curiouser.

So to generate a split phase 240vac 60hz waveform, we have to go to battery backup. Predictably enough, any small inexpensive versions of that are ALSO limited to 120vac single phase. You can't simply use two of them. There is of course a phase relationship between the two phases to achieve the 240vac.

So I went back on eBay and had to find a refurbished and probably obsolete UPS battery backup system. We'll have to use THAT to generate the 240vac 60hz so the Aurora will have something to synch to. All this so I can use one of the cars as a battery backup. Since I have a generator, I don't even need this. I just wanted to demonstrate how to use an electric car to backup your house easily, if not inexpensively. The 6kw Aurora is already about $4000.

If any of you know of a small inexpensive circuit to convert DC to 240vac split phase, I'd like to hear about it. It doesn't need to make any power at all - just present the waveforms at milliamperes of current really.

The device actually DOES accomplish what I actually DO need. We often have to discharge a car to a low battery level to set fuel gages etc. It's a shame to just dump off that energy with the heater and waste it. Now I can plug a car in, and use the discharge energy for something useful, like running my house, while I discharge. But using it as an emergency backup just won't work, without buying a battery backup UPS system, which is what we are wanting to create. Kind of a circular chase, and all entirely unnecessary. This "safety" system is useless, and I would encourage anyone doing any kind of alternate energy power system, be it generator, solar, battery, wind, or whatever, to STILL get an automatic AC disconnect switch in any event.

Basically, this switch is just a huge transfer relay. It uses grid power to close a relay connecting the grid to your house. If you lose grid power, the relay deenergizes, connecting you to your alternate system, and in the case of a generator, also starting the generator.

If you get grid power back, it closes the relay, connecting you back to the grid, and disconnecting your house from the alternate source. This always did work most excellently. The "anti-islanding" built into the individual components looks very suspicious to me.

Again, if you know of a little inverter, even to work off a 12v battery to make 240v split phase waveform, we would like to hear about it. Note that there ARE 240v inverters, but these are single phase for European applications - it is NOT a two phase inverter.