tag:blogger.com,1999:blog-6676835811534572362.post6840749035126843696..comments2024-02-06T10:02:20.731-06:00Comments on EVTV.ME: This Week on the Mini CooperJack Rickardhttp://www.blogger.com/profile/15936311474215791697noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-6676835811534572362.post-89438840185204308832009-11-20T23:05:29.164-06:002009-11-20T23:05:29.164-06:00Hi Jack, i had just watched your video
about shun...Hi Jack, i had just watched your video <br />about shunt-balancers!<br /><br />You did exactly hit the point!!!!!!!<br /><br />(i didnt see it that clear before)<br />last week i did some development of a<br />balancer system based on a cheap<br />attiny13 controller.<br />(I want to use an attiny 25 later)<br />and of course there is a display for <br />undervoltage! Thats the main reason <br />for starting the project at all.<br />I was missing this basic information<br />in so many systems.<br />The project is far away from being ready<br />at the moment, but you can read the <br />actual source-code on my blog.<br /><br />The last hex-file is also there.<br /><br />http://vehikelfranz.blogspot.com/<br /><br />Its in german language, but<br />if necessary i can translate it<br />for You. <br />I will implement some kind of<br />M-BUS (Meter-Bus) for reading out the <br />actual voltage of every cell.<br />A Master calls the number and the<br />cell that is called will answer<br />with its data.thats very easy to program.<br />M-bus means, all units are in a row<br />The master sends by voltage changes<br />the slaves anwer by current change,<br />so, only two wires are needed<br />for all the informations <br />and it is much easier to manage than<br />a CAN-BUS.(simple RS232-protocol)<br />I also implemented a balancing limit<br /> and an overcharge-limit<br />under- and overvoltage detection use the same pin at the moment<br />As you dont like the shunt-balance<br />function, simply dont use it or use it for a<br />pre-warning for low energy or to<br />stop charging.........<br />Programming these attinys is so simple.<br />And they work from 1.8 to 5.5Volts<br />and they have a voltage reference on board.<br />You surely will find somebody who<br />knows how to do it in your neighborhood.<br /><br />The item Mother-Battery is so <br />interesting for me, because in the<br />sawmill of my parents there is<br />waterpower of 25KW and a solar-unit<br />of 30kW on sunny days!<br />And often all this power is not needed!<br />I could get my energy there, but this<br />is about 1 mile away,<br />so i want to transport it in a trailer.<br />(i dont have an EV at the moment)<br /><br />Thank You for those wonderful videos!<br /><br />Franzvehikelfranzhttps://www.blogger.com/profile/10449865940679907208noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-34256094416292894622009-11-19T04:46:35.627-06:002009-11-19T04:46:35.627-06:00Me once again!
This requires knowledge about
the ...Me once again!<br />This requires knowledge about <br />the controller that is used.<br />As many controllers switch<br />to ground because N-Channel MOSFET<br />are better for high currents <br />it might be necessary to connect<br />both piles of Batteries at the +pole<br />and to regulate at the side of the <br />-pole.<br />Its a bit tricky, but nevertheless<br />it should work! but be careful!<br /><br />Franzvehikelfranzhttps://www.blogger.com/profile/10449865940679907208noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-64921047245602603412009-11-18T16:46:41.857-06:002009-11-18T16:46:41.857-06:00Jack, if you connecct a controller only to the par...Jack, if you connecct a controller only to the part of batteries that are higher in voltage than the pile that is to be loaded,the <br />controller does not have to be a high voltage type.You dont have to regulate the whole voltage.You may start at the point which<br />is the lowest to be expected in the pile<br />to be loaded.As everything is in a row,<br />the current will stay the same in the <br />whole pile except the consumtion of the controller itself.<br />(i already posted this a few minutes ago at a very different place in your blog, sorry)<br /><br />greetings from germany! (Bavaria)<br />Franzvehikelfranzhttps://www.blogger.com/profile/10449865940679907208noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-23777355688824267322009-11-12T21:23:32.421-06:002009-11-12T21:23:32.421-06:00Hi Jack, I know you tested a bunch of DC-DC conver...Hi Jack, I know you tested a bunch of DC-DC converters before coming up with your homebrew Vicor solution. Have you come across anything, short of homebrew, that would handle a 205v nominal LiFePO4 pack? Can you run Kelly's in series?Jeffhttp://www.adventure-ev.comnoreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-12079915284709703782009-11-09T14:35:17.541-06:002009-11-09T14:35:17.541-06:00Sorry, I posted this comments to the wrong place e...Sorry, I posted this comments to the wrong place earlier:<br /><br />Jack, to do bulk DC-to-DC charging, have you considered using a motor controller, for example a Zilla? Have a higher voltage pack connected to the Zilla's input. Connect the Zilla's output to the lower voltage pack through a large inductor. Set the Zilla's current limit and turn it on. You should be able to get lots of amps flowing that way. A little extra circuitry could shut off the Zilla when a certain voltage was reached--or even just a simple timer if you didn't want to get too fancy.<br /><br />BillAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-85279669097039672912009-11-04T09:41:16.890-06:002009-11-04T09:41:16.890-06:00That's all i could come up with as well. Using...That's all i could come up with as well. Using a curtis that could handle the power and then a trim pot for its input. My voltage is much lower however about 157V so there is no issue finding a controller for it. I suppose using 3 and spitting the load 3 ways would work ultimately with some mucking about at high voltage but you are more of an expert at this than I am. But, how much do you want to spend to charge quickly when you really dont have a need to do so. Perhaps just for testing reasons you could hook up 3 inputs to your pack as well and charge 1/3rd the cells at a time in 20 minutes. (Or get 3 controllers with 3 inputs and do the whole pack at one time since you cant find a high power high voltage one.) That way you could prove the method get a close to fully charged pack in an hour (or 20 minutes if you go the 3 controller way) when needed. Odd i sag so much when it gets cold. I am going to have to check all my connections again.dexionhttp://saturnev.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-20819821052570884972009-11-04T09:15:31.513-06:002009-11-04T09:15:31.513-06:00I do use an automotive relay. It's a little h...I do use an automotive relay. It's a little heavy - a 40 amp 14 volt relay, and yes we are using it to switch 375 volts - at about 5 amps. So far, arcing hasn't been a problem. There is a very wee filter cap in the device, so there is no big inrush situation. And arcing hasn't been a problem.<br /><br />No issues with low temps. Probably a little less peppy, but we did a lot of test driving in February down around 20F and the car did much better than the driver. Of course, we had the heater on, and the cells warm up naturally from producing currrent. My experience has been the problems with cell temp are all about getting rid of excess heat, not keeping them warm.<br /><br />Yes, more thoughts on the "mother lode" but I need basically a car "controller" for the PWM that will do well over 400 volts and 300 amps. That's a little hard to find at this point. Same old problem, more power.<br /><br />We would probably have to start with a series of contactors to select output voltages by tapping in different batteries.<br /><br />Jack RickardJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-18750487008689811802009-11-02T10:11:13.002-06:002009-11-02T10:11:13.002-06:00Jack,
In the Oct. 28 Friday Show, you say that y...Jack,<br /> In the Oct. 28 Friday Show, you say that you use an automotive relay to switch on the paralleled Vicors. In your Oct. 31 blog diagram, you show that relay switching the full 375V. I thought automotive relays are rated only at 30V. Are you actually using some other relay?<br /><br />Thanks.<br /><br />BillAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-19997124753770147002009-11-01T21:24:50.384-06:002009-11-01T21:24:50.384-06:00Mr. Rickard,
Have you thought any more on a pwm t...Mr. Rickard,<br /><br />Have you thought any more on a pwm to handle your mother battery pack? I would be very interested in how you decide to attack this problem and ultimately what you do. Any issues with the speedster and lower temps? I find my TS cells do not like the cold. They seem to sag much more. Keep up the good work both of you.dexionhttp://saturnev.blogspot.com/noreply@blogger.com