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Discussion Starter #1
Hi, Probably a question that has been asked many time but I didn't find a thread with the info I was after.

I've converted a Smart Roadster with a Curtis 1238/6501 Controller and AC35 motor. I bought 12 used Leaf batteries and the car is basically running and almost ready to put on the road.. except!... partly due to a lack of knowledge, I haven't sorted out the battery charging.

I've done the conversion on the cheap, sourcing parts from ebay over the years but it's always suffered from a lack of time so it's taken me a long time, the car really has to be on the road this year otherwise it's never going to get finished.

So my question is, what off the shelf system do I just need to go and buy to end up with a suitable BMS and charger that's just going to work for these cells?. I've periodically looked around but it's never clear what I should buy.

In short the spec is 24s 3.6/4.1v cells so peak 98v, I'd prefer a BMS but presume it's best not to use the cheap chinese ones.. are there any nice chargers, within a reasonable budget that would suit this setup?.

Many thanks for any help.

Paul
 

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Here is an idea for you, if you are mainly going to charge at home (like most folks do), and you are not likely going to use J1772 for charging, then you might consider finding a used laboratory power supply on the GSA auction site that has both voltage and current control.

You can set a current limit, then set an upper voltage, and let it go. The size and model of power supply will be determined by whatever maximum current that you desire--but considering you are using laef cells with their poor thermal history, charging at too high a current wouldn't be recommended.

i've gotten some really expensive and great power supplies for very low price, dirt cheap, e.g. a 150kV xray power supply for $50. That is an extreme voltage level, but HP made a 1kW 200V 17Amp supply that runs on 120vac wall outlet that is bullet proof, also a 100V 30A version. Obviously they can't do both at the same time. There are lots of high quality power supplies out there being excessed by your uncle sam.

Your other option is to shell out some bucks for a chinese charger, and good luck with that quality...

Figure out your charging current requirement, you already know your voltage. From there can you determine the power, then double it, and that's the power rating size that you want to look for.
 

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Hi, Thanks for the reply.

I'll hope to charge at home and at work, we have free charging at work so I'll make best use of it. I have a J1772 home wall unit from when I used to lease a Nissan leaf a few years ago so hope to make use of that.

I have considered a PSU and occasionally have a look on ebay for something as a temporary fix but was hoping to find something more permanent, I guess I could always just fix the PSU in the car and carry it around for now.
I'm in the UK so not sure what GSA is, I don't think we have anything similar, it's quite hard to find many used parts here at a decent price. However, there is a 100v 12A PSU for £200 at the moment so I might give that a go.

Next stage will be to get the car inspected and verified for the road, but I don't think the garage really know what they are looking at (only that it no longer has an ICE) so I suppose I can build it with any type of parts.

Thanks for your ideas

Paul
 
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