Prismatic cell case shorting

[MadMax03]

Is there a definitive answer about EVE cells or any other aluminum case blue-wrap cells shorting out on each other? I'm building a 120ah 12v battery for my Mercedes with 12 40ah cells, so car application. Will they short out on each other if the metal casings come into contact with one another?

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I can't find anything on this site that is definitive. Nothing in the data sheets for these cells, nothing in the data sheet for EVE cells, I just want to know if I need to insulate between the cells or not. I can figure out the what/how. But in a high-vibration car application, I want to make sure I need to. The box I'm putting these in will JUST fit the 12 cells going into it with 1mm acrylic square sheets I already ordered, and I'm going to install them anyway, but I'll worry less if they fail somehow if I know that nothing will happen if they somehow did.

Thanks!

 

[brb58]

Yes, if that thin blue wrap wears through, the cases WILL short to each other. You must put additional insulation between them.

 

[MadMax03]

Thank you. I ordered these and cut them to size:

[10-Pack] SimbaLux® Acrylic Sheet Clear 8”x10” 0.04” Thick (1mm) Plexiglass | eBay

Acrylic Plexiglass Sheet (Common Size). If the sheet cover is difficult to remove, try to use an alcohol wipe to rub on the sheet cover at a corner to help remove the sheet cover. Transparent Clarity.

www.ebay.com

 

[joanna_lannie]

Agree with brb, but ensuring the integrity of the blue insulating film should be something the merchants who sell the battery to you need to do. The installation of an insulating plate is the second layer of protection you can do, and it is also recommended to compress the battery slightly, which can prevent your cells from bulging and achieve the best performance.

 

[MadMax03]

I'm on the same page with the consensus regarding compression, and was involved in some of the earliest threads regarding the subject. I'm the first guy that I know of on the forum that introduced/posted the EVE cell data sheet section that had compression info, so I get all that BUT, on that note, several of these cells have a slight (maybe 0.1mm?) convex to them, and won't sit flush with the next cell. I'm not really worried about it though, and will compress them slightly with a ratchet strap in the middle, then wrap above and below the strap with 2" kapton tape and call it a day. Being a car application, they will never fully cycle, so there's no point in even trying to squeeze out 30,000 cycles with compression vs 25,000 cycles uncompressed because no cycle data exists in a full charge situation so I'll never know anyway.

I'm doing 4S3P to get my 12v. Using this box too, in case anyone is interested. I'll get pics up if anyone wants.

DIY49 - DIY Central Shop

DIY 49 Battery Housing with Terminals, Unglued, Dividers Removed, Labels Included. DIY housings will arrive with the lid and hull separated.

diycentralshop.com

 

[Yurtdweller]

I installed thin HDPE vegetable cutting mats from kitchen supply in between each cell. They're less than a millimeter thick, can be cut with scissors. Flexible, abrasion-resistant and won't abrade the shrink wrap.

 

[mrzed001]

Is there a definitive answer about EVE cells or any other aluminum case blue-wrap cells shorting out on each other? I'm building a 120ah 12v battery for my Mercedes with 12 40ah cells, so car application. Will they short out on each other if the metal casings come into contact with one another?

161.89US $ 30% OFF|HAKAID 3.2V 40Ah Lifepo4 Rechargeable Batteries Brand New Grade A Lishen Original Cell For DIY 12V 24V 48V Ebike Scooter|Replacement Batteries| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

I can't find anything on this site that is definitive. Nothing in the data sheets for these cells, nothing in the data sheet for EVE cells, I just want to know if I need to insulate between the cells or not. I can figure out the what/how. But in a high-vibration car application, I want to make sure I need to. The box I'm putting these in will JUST fit the 12 cells going into it with 1mm acrylic square sheets I already ordered, and I'm going to install them anyway, but I'll worry less if they fail somehow if I know that nothing will happen if they somehow did.

Thanks!

Never thrust the blue wrapping
There was already a case where it failed:

Short through cell film

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