Mechanical Compression of LiFePO4 Pack: Necessary?

F

frogblender

10 mW
Joined
May 27, 2012
Messages
30
I have a couple of Lifepo4 pouch packs.

A pouch has next to no structural integrity to it.
Prismatic cells, OTOH, usually have a more rigid (sometimes aluminum?) enclosure. Same goes extra for cylindricals, whose round geometry can withstand substantial internal pressure.
My cheap chinese lifepo4 pouch packs seem to be wrapped semi-tightly in: plastic cling-wrap, then thin & flimsy FR4 (or something similar), then duct tape.

I've read things about "compressing the layers" here and there, and various voodoo to resurrect puffy pouches, but nothing definitive.

So the question: Do Lifepo4 pouch cells require mechanical compression?
 
I don't know if the cells " require " it , but a pack of cells assembled together should be secured by a layer of rigid plastic ( non conductive ) and some compression to keep the pack solidly packed.. preventing damage to the tabs from wiggling around etc...

I compress all my packs slightly and secure them with filament tape that does not stretch.
http://ypedal.com/Chaos/Chaos6.htm

( see half way down )
 
Compress at least enough to protect them for sure. At the very least, you don't want to crush a corner, or rub holes in it, and that means some kind of fairly tight container

So at a minimum, they grow into the box, and start compressing themselves.
 
As the other guys have pointed out, yes I understand that the cells must be contained enough to prevent tab wiggling and corner crushing and the like. That's a given.

But I'm talking about 100 pounds kind of force, or more. Perhaps much more. Somewhere I saw a picture of a guy sandwiching a moribund cell with a handful of C-clamps.
 
Hey. Yes compess. But I just Megawraped. With my A123 pouch cells 15-20 C cells but used at 30a. So how good your cell. Yes tell us more ? 50 C cell or .05 C cell ? More info.
 
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