this post was submitted on 18 Oct 2025
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18650 battery pack 16s2p design (imgur.artemislena.eu)
submitted 1 week ago* (last edited 1 week ago) by Rolive@discuss.tchncs.de to c/diy@slrpnk.net
 

This is a design I'm working on. The idea behind the wave pattern is so that they can be stacked without losing all too much space compared to rectangular cell packs.

I'm putting a 60C thermal fuse in between each cell pair. Should a cell overheat, the fuse will pop and render the pack useless. This is an additional safety feature on top of a BMS and periodic manual checkups with a thermal camera.

The idea behind all cells pointing upwards (positive facing up) is also a safety feature. Should one start to vent or catch fire the flames will go up immediately triggering an extinguisher above the cell pack.

Let me know what you think! I'm not finished with it yet but if you want the design files already let me know I'll send them to you.

Edited with a deshittified version of imgur.

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[–] czardestructo@lemmy.world 3 points 1 week ago (2 children)

May I ask why 18650? 21700 have better energy density and theyre easier to get these days. The price has also come down a lot.

[–] Rolive@discuss.tchncs.de 3 points 1 week ago (1 children)

Because I have a metric shitload of them available. Indeed if i was going to order fresh cells 21700 is better especially for a home battery system.

[–] czardestructo@lemmy.world 4 points 1 week ago

Way better to use your old junk. I like that youre make your own home battery, ive considered it. I have solar installed and would love to not consume grid power at night. I'm thinking of installing a bank of lead acid batteries under my ground mount solar that would dump power into my home at night.