Pulled the trigger, need a box...

[brb58]

How do I space them apart? I use the terminal adapters that I designed and 3D printed. They provide about 2.5mm of spacing between each cell, while still holding two cells together so they don't move.

I have also just added a 1/4 hole through the side so that I can then fix all the cells together so they don't separate. I'll use a 1/4 all thread rod through the length of the battery bank. This is NOT used for compression, just to fix them in place for terminal stress relief.

No...how do you keep them from swelling more than 0.5mm?

 

[RoySalisbury]

unclear which dominates degradation mechanism. looking for answers and questions.

allowing cell flexture (e.g. not fixing with cell walls pushing against each other) is deemed allowable and safe by most manufacturers of cells.

therefore, it is a operational lifetime tradeoff, not a SAFETY tradeoff.

I'd also like to see some documented information on cell lifetime when compressed vs fixed. Everything I have read in the specs says "fixed" ... Are people just assuming they need compressed because someone else did it? I'd really like to know for certain .. if I am wrong I would like to know now and not in 3 months when I have everything installed.

 

[RoySalisbury]

No...how do you keep them from swelling more than 0.5mm?

I'm sure they can if they get warm enough and get over charged. I've seen pictures of them swelled 5 or 6 mm ... But in that case, the swelling is a sign of a problem that needs corrected and not something that should be "expected". But the manufacture specs for the batteries I have say that swelling of .5mm is normal, so thats what I account for (plus a little extra).

 

[brb58]

I'm sure they can if they get warm enough and get over charged. I've seen pictures of them swelled 5 or 6 mm ... But in that case, the swelling is a sign of a problem that needs corrected and not something that should be "expected". But the manufacture specs for the batteries I have say that swelling of .5mm is normal, so thats what I account for (plus a little extra).

You are going through all the trouble of 3d printing a fixture. Pretty easy to prevent swelling by keeping them secure.

 

[RoySalisbury]

You are going through all the trouble of 3d printing a fixture. Pretty easy to prevent swelling by keeping them secure.

The fixtures are also for safety and wire management. . Plus they look better than kapton tape over the terminals.

 

[Rednecktek]

I really like that Noco box, and it's cheap! So, back in the neighborhood of the OP guys...

My plan is to make 2 boxes total. One of them is 4x 230Ah on a 4s JBD 120a.. left black for my brother's pop-up
The other is going to be a JBD 4s with Heater support... painted white since it's for colder weather...

I'll grab some of the 6w 12v heaters for the battery, but where/how to mount the heating pads? Aluminum plate on the bottom? Bottom and both sides?

 

[740GLE]

I’d just go with the bottom, IMO is not so much as heating the cells be preventing them from getting too cool. Have it come on around 5c.

 

[prhittle]

I built my bank with the DOCAN 304 AH cells. I used the new SOK BMS and it all fits nicely in the NOCO battery box pictured. Battery box is $12 at WalMart and it comes with a strap to secure it and a cover that easily fits over the cells and wiring.

View attachment 95851

View attachment 95852

I built my bank with the DOCAN 304 AH cells. I used the new SOK BMS and it all fits nicely in the NOCO battery box pictured. Battery box is $12 at WalMart and it comes with a strap to secure it and a cover that easily fits over the cells and wiring.

View attachment 95851

View attachment 95852

Looks like the top just snaps on...is it watertight?

 

[Gould]

I just ordered 4 of these. A bit pricey, but ships from USA.

ABS Battery Box for EVE, LISHEN or CATL 271 – 310AH Prismatic Cells – Solar Supply House

solarsupplyhouse.com

Do you have much air time with these boxes? Any concern that you can’t compress the cells? I went the way of DIY and unfortunately they didn’t hold up well - I have no choice but to put them on the hitch of my travel trailer. They’re inside a larger box but I just can’t get the box air tight enough to prevent condensation on the cooler nights. These look like they’ll fit the bill but curious if your longer term review.

 

[meetyg]

Do you have much air time with these boxes? Any concern that you can’t compress the cells? I went the way of DIY and unfortunately they didn’t hold up well - I have no choice but to put them on the hitch of my travel trailer. They’re inside a larger box but I just can’t get the box air tight enough to prevent condensation on the cooler nights. These look like they’ll fit the bill but curious if your longer term review.

I'm using the same box, but for an 8S 24v battery, with 105Ah cells. I got the box from Aliexpress, originally intended to build a 4s 280Ah battery, but hadn't gone through with it.

https://www.aliexpress.com/item/1005003229230174.html

As for compression, the box is pretty sturdy. Maybe you won't be able to get as much compression as you would with a DIY enclosure, but I think some minimal compression can be achieved.

On my 8s pack, I put EVA foam in between the cells as a separator and for compression. At the end of one side I used some packaging foam because I didn't have EVA thick enough. But believe me, it was really tough getting that last cell in between.



This is a recent build, so I can't say how it holds after time. But I can say that when the cells were inserted, they were at around 60% SOC, and then I did a top balance, so I would expect some expansion, but I don't see and cracks or anything like that on the box.

So far so good...