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Boston Power Swing 4400

2634 Views 9 Replies 5 Participants Last post by  tylerwatts

I have been reading this forum for quite some time and have finally got round to starting a conversion. I'm hoping to start a build thread but for now I have a couple of questions on batteries.

I can get hold of some Boston Power Swing 4400 lithium cells ( at what seems like a decent price. They are not brand new so I'm a bit wary but I haven't got a huge budget so my lithium options are limited. They apparently came out of a prototype electric van when the company developing them went bust.

Does anyone have any experience or advice on this cells? There seems to be nobody using them and I don't know if there is a good reason for that!

Is there anything that I can do if I go and have a look at them to test what kind of state they are in or whether there are any bad cells?


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Your best bet is to find packs from recked electric cars.

Nissan Leaf is one of them.

"Lithium" covers a wide range of battery types.

What specific chemistry are those, and what others may you be considering?

Edit: wow, tiny capacity! Are they a small cylinder form factor like 18650 where you have to weld them together to make a large bank?
Leaf batteries are an option. I had been looking into them before I came across these batteries. The specs seemed ok and the price is a lot cheaper than I can get a leaf pack for.

Yes, they seem to be two 18650 cells in a single oval shaped cell. The ones I am looking at have already been welded together into packs of 8 cells in parallel. I would be looking to put two of these packs in parallel to get 16 cells in parallel (3.7V 70aH). Then put 80 of these in series to get 296V.
The chemistry is LiCo I believe.
Very interesting, thanks. Seems like they may be worth a try as long as they haven?t been abused in their previous life.
Hi Tom
LiCo is a very good chemistry for a small battery with high power and fast charging and keeping a good life. These should be great for your build if you have a good way to assemble them.
Do you have any pictures?
I did end up purchasing these batteries. They came assembled in packs of 48 cells (6s8p) in a really nice case as they had been used previously in a prototype electric van. Unfortunately I don't have any photos, I will try to get one soon.

I'm planning to make a slight modification by connecting them in a 3s16p configuration to give me the voltage and amp hours I need. I have 28 of these packs (1344 cells in total). I might not be able to squeeze them all in but I'll use as many as I can.
Sounds very promising, and as was said, great conversion vehicle in my opinion.
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