DIY battery enclosures

cycborg

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I think this is an under-discussed aspect of battery building, so if this evolves into a general discussion of ideas/solutions/resources, I won't mind, but I am hoping to get some input on my specific situation.

I'm building replacement batteries for an electric scooter, the Evader EV1000. It shipped with SLAs, but by the time I got to it, it didn't have any batteries at all. However, it does have custom battery trays that I'd like to take advantage of.

My first thought is that if I could get hold of SLA shells (i.e., SLAs without the L or the A) in the right size, I could pack them with 18650s and just slide them into the trays and tie them down.

Alternatively, I could find any other box that's the right size, and make some terminal connections through the lid.

However, I'm having a tough time finding boxes that are the right size, for some reason. The trays are 8" wide by 7" deep by 5-3/4" high (170 x 195 x 140 for those of you who use sensible units), although the box could be taller since the trays are open at the top. Of course, I'd like to pack in as many cells as I can, leaving room for BMS, insulation, terminal wiring, etc. So vertical sides, squared edges, and no protrusions would be best.

Should be reasonably rugged and waterproof. Any ideas where I could find such enclosures?

Thanks for your ideas.
 
You could check with your local powerchair / medical supply places and see if they have old dead SLA you could rip the guts out of. UPS/server backup power units also use them, so places that service those may also have them. Local recyclers may have piles as well.


You can fabricate shells in a number of ways, and probably make better-shaped ones that simply fill the tray(s) of the Evader without wasting the extra space taht individual "battery boxes" would. (you might get a few more cells in there that way).

Would also save on external interconnect waterproofing, as almost all of your connections would be inside your new shell(s), except for the main + and - to the Evader. Evertyhign else would be inside; easier to waterproof.


There are a number of threads about building battery cases, but the biggest collection is here, if there's anything useful in it for you:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=12847
 
cycborg said:
Thanks, I might go with your suggestion from that thread for ABS forming. I did a little searching elsewhere and found this step-by-step.

I was looking for a plastic enclosure for my 14s4p that is built like a rectangle with cell holders. Found this plastic box, it's pretty sturdy and the battery fits in with plenty of room. I will cut about an inch off of the top to fit my battery better then use great stuff foam to lock it into place. After that I'm gonna make some kind of lid to make it waterproof.

https://www.amazon.com/gp/product/B00A17UK48/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
 
I Agree with the OP. Building DIY battery boxes is very time consuming, and unfortunately a one-off every time. It would be quite useful to start a sticky thread listing readily available solutions for common cell configurations. For an instance, it took me forever to figure out a lightweight, stylish and solid box for a simple 13s2p battery, until I found this bottle The 1L version is a perfect fit for 26 cells + bms, and the opening is large enough to accommodate any charging plug, even a big rosenberger. Just cut out a 2cm ring somewhere in the upper part, use this ring a collar to put the bottle back together (I epoxied it to the lower portion) and you're set. Best way to fasten it are larger stainless steel pipe clamp drilled with a 5mm hole and directly mounted onto the bottle hole of the cage. 2hours job (including epoxy setting time) for a perfect box ... dirt cheap.

Check out the result here
 
Amazing topic. This is sooooo overlooked....
For some reason everybody seems to skip this very important topic,as if it didn't matter...
I did ask myself these same questions and I still do now for some more recent battery builds...

Links to things i found:
Finding large premade battery enclosures: https://endless-sphere.com/forums/viewtopic.php?f=14&t=88415&hilit=empty+downtube

Matador
 
I also love these homemade aluminium box...
14S10P, so you'll never have any sort of range anxiety before you butt can't take it anymore:

[youtube]55xQxCVH3To[/youtube]

Matador

I need a TIG welder... that is the solution to all my problems...
 
You might try looking for "display batteries" which are made without the guts for auto parts store displays.
 
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