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using prismatic cells in a custom battery box?

Posted: Sat Jul 06, 2024 11:41 am
by Jacobsmess
I'm considering reassembling the modules from the Lexus UX300E that I've got. They use Panasonic prismatic cells (datasheet attached), but the modules are quite long and large. They can be broken down easily by drilling out 8 rivets and then you get 288 individual cells with screw terminals.
If I were to go this route, what would be the best/safest way of repackaging them?
I assume I'd need some insulation between them. Repackaging would also open up possibilities of liquid cooling whereas before I was stuck with making an air cooled pack.
Any thoughts? I suspect the best approach is to stick with the OEM modules and making it work somehow but just looking at ideas, thanks.

Re: Custom battery box using prismatic cells. Anyone done this?

Posted: Sat Jul 06, 2024 11:46 am
by tom91
This would be yet another level of complexity riddled with potential errors. Do you really want to make things even more complicated then they already are?

One thing to note, these cells require a certain amount of compression to keep them from bulging and failing prematurely.

Re: using prismatic cells in a custom battery box?

Posted: Sat Jul 06, 2024 12:22 pm
by Jacobsmess
Yes I understand that hence my asking for considerations.

Re: Custom battery box using prismatic cells. Anyone done this?

Posted: Sun Jul 07, 2024 9:52 am
by Jacobsmess
tom91 wrote: Sat Jul 06, 2024 11:46 am One thing to note, these cells require a certain amount of compression to keep them from bulging.
Well I've just discovered this. Prior to posting I had broken down one module on order to see how easy it was to resize it and split it across to battery packs, but not I cannot get it to fit back into its original size (held together by 4 steel braces).

My plan is to bolt some angle steel to either end of the module and then use some threaded bar in order to slowly compress the cells again and hopefully get them back into the original steel braces. Any thoughts on this new level of idiocy?

Re: using prismatic cells in a custom battery box?

Posted: Sun Jul 07, 2024 1:22 pm
by tom91
Make sure to spread the compression force, as not to dent the prismatic cans.

Had a hunch you would already split a module and then ask questions. You better ensure you remove any busbars before removing the compression.

Re: using prismatic cells in a custom battery box?

Posted: Mon Jul 08, 2024 6:35 am
by Jacobsmess
All bus bars were removed prior to the module being disassembled.
Compression will be applied to the outer casing not the cells directly, which I suspect is how it was originally assembled.
The cell spacers have ribs but are also very flexible so I suspect a lot of the actual compression will be taken up but these. With the end caps being made of some tough ABS type material and then some plate steel that I will be bolting my compression tool to.