Understanding lithium for Gems

Found it.

Yes, those are the batteries that I bought. There are 6 at 12v, 100AH each. I heard back from Dakota and they indicated that two sets of 36v can be connected in series for 72v. They said nothing about the pulse rating. I just sent them a wiring diagram showing the main disconnect switch which is tripping. Do you know what the purpose of the 100a rating is for the main disconnect? Can I make this work??

It’s my understanding that it’s a service disconnect, not a circuit breaker. Are you sure it’s tripping?
I’ve heard of them burning up, but not tripping.
I would expect the batteries to trip. The lfp batteries supplied for Polaris Ranger, often require that the controller be sent in for detuning. Learned this on the Polaris Ranger ev forum.
I would test the switch if it’s not obvious that it has tripped. Such as being in the off position.
The part number was given on this forum. Let me look for it to see what it is.

I am thinking bad disconnect - Grant and Troy have run into the same thing.
As you stated before it is not uncommon for them to go bad. Had a buddy here in KC have one go bad as well.

There is another thread @grantwest looking for a replacement. It was never put to bed.
Troy tried using a circuit breaker, which of course tripped and blew up.
I need a part number to confirm. A “0” in the part number signifies “switch only”.
A 100a continuous switch will be fine as long as it is never opened under load.

I think this is the thread - be ready to get confused… LOL

Part number 0606-00445 switch disconnect.
As I suspected.
@nfeenstra The bms may be tripping and is reset by power cycling.
Before resetting check each battery voltage and also voltage drop through the main switch.

I did a Lihitum conversion on my Buddys ken’s car. And guess what it MELTED the breaker.
I took Dave’s advise and I also Agreed with him because it made sence that breaker is Usless. Once ken’s car melted the breaker I simply tied the 2 connections together and have no regrets. You don’t need that breaker

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@Inwo That seems to make sense. When the power goes completely black, I turn the switch off and then on again which resets the bms. I will do some testing on the batteries tomorrow.

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When the power goes completely black, I turn the switch off and then on again which resets the bms.

Ah! So - The disconnect was not physically moving to a tripped position? You were actually flipping it off and on yourself? (assuming it was internally tripping?) This is making sense now.

I’ve been itching to get lithium batteries for my 2005 e4, but I want to get it right the first time.
Will the two Dakota batteries work ok? Just looking to get ~20 miles in a somewhat hilly area.

@Inwo mentioned that 350a minimum is needed, and since the Dakotas are 100a/200a-peak, does that mean I’d actually need 4 of those 36v batteries to achieve ideal specs (2 sets of two batteries connected in a series connected in parallel)?

I’m going by what I remember from high school science class from over 20 years ago, so let me know if I’m way off.

I have not worked with the Dakotas. Depending on your Gem setup, it will pull 300a for about 2 sec., then drop to 200a for 5 sec and then settle in around 100a. you need to check with Dakota and see if 2 can be out in series and if they can handle the pulse loads. My guess is they would work, but just a guess

I’m no fan.
There is nothing to make parallel batteries share the load evenly. And, nothing to keep series batteries at the same voltage.
Imo, series parallel with multiple bms is a cluster ****.
If I had the batteries for free, would pop them open and wire them correctly.

Thank you, both. @Inwo any idea when you will have more batteries to sell since @LithiumGods says he won’t be getting any more till the end of the year?

I have a huge 24s Tesla3 battery. 225ah 20kwh.
At 40" long it’s a tight fit in all but a truck.
Good news is that it’s complete, assembled with bms and LCD, ready to drop in.
One Tesla3 module left that I can custom build as short as 20s and 33" long.
See @Erniea15
Also have a Honda ev battery coming in next week. Don’t know what it is yet.

@Inwo split a Tesla battery to fit my 2016. Actually had to give it 2 tries since the first one wouldn’t fit in my car. It came drop in ready with the BMS. I was like a kid waiting for Santa to come as it was shipped across the country. I’ve been gathering parts to dive into this project. Soon enough. I’m excited to see what kind of range I’ll get. I’m guessing I’ll only need to charge the car once a month :wink:

I have some Chevy volt packs in my garage if that’s something you’d be interested in. Been holding out on them for a golf cart hot rod project… but that might not happen until the fall / winter.

@djgabriel2004 might have a bolt pack that he’s willing to part with… I know someone else was considering buying so they might be gone.

Car-Part.com - Used Auto Parts Market is a good place to look for junkyard parts. I found my full Chevy volt battery on this site. Got is delivered for 1800. They have some telsa model 3 batteries listed too.

Thanks for your response.

I spent the last three days reading up but somehow missed the last two posts on this thread until now.

@Inwo helped me pick out LiFePO4 batteries from Aliexpress on another thread, so I went ahead and purchased them. Well the sale is still pending because I guess it raised red flags with both Aliexpress (new customer) and my credit card company, so I have to wait until Aliexpress completes validating my ID, CC…etc.

I believe @djgabriel2004 already sold his bolt pack to the other person, or else I would have been all over that.

I can still back out of my Aliexpress purchase, so just want to review how the Chevy Volt packs compare to the LifePO4s that I was going to buy. Please keep me straight if my understanding is incorrect.

Range: I think they’d be pretty similar, but it looks like they’d be much smaller and lighter, so easier to install.
BMS: From what I’ve read, it seemed like LifePO4s may NOT require a BMS.
Charger: I have a 2005 e4, with what I’m pretty sure is not a reprogrammable Delta-Q 910-7200 charger. I think some have gotten the LifePO4s to charge without needing to be reprogrammed, but maybe those were just the lucky few.
Price: I’m assuming the Volt batteries would be more expensive. Can you quote me a price including shipping to zipcode 99224?
Longevity: Not sure
Power:I live in an hilly area, and am I correct that the total voltage is what matters for this? I was looking to go with 72v (24 cells) for the LifePro4s.

@Inwo - I also just saw your comment about smaller Tesla batteries and a possible Honda option.
Based on previous posts from others, I assume those options to be pricier than both the LifePro4 and the Volt batteries. If you can quote me a price to 99224, I’d much appreciate it. I am assuming I’ll need to add the price of a BMS (~$300) and a new charger (~$300) to the price. Is there anything else I’d need?

Thanks so much for your help!

I should have the Honda battery next week. Haven’t seen one, but believe it similar to the Volkswagon E-Golf I had previous. That will make a great Gem battery.
Yes, anything other than lfp needs a bms.
A custom Tesla3 is $3500. Includes bms, LCD, and some type of enclosure. Ready to plug in with two connections. Shipping is freight or uship from 55941. 200 lb. 225 ah.
The Honda will be less money, and be prewired if you like.
It’s the light weight that helps on hills.

E-golf battery module.


s-l400-1
Takes 5 of these.

That is funny, I almost grabbed some of these locally a couple weeks ago.