Battery location crawl-space or outside in metal shed

[tweekzilla]

I'm currently debating the best place to store a 16s2p battery pack (280ah cells). One option is under the house where it should remain cool but under the house makes me somewhat nervous even if LiFePO4 are supposed to be safe. This should keep them out of direct sunlight and generally cool (This is in SoCal). Another option is outside in a waterproof metal shed but it is likely to get warm (expect about 120F in summer) so will probably require cooling of some sorts - i.e. a pain.

Any other/better suggestions?

 

[mopat]

dig a pit outside near charge controller line with plastic and polystyrene

 

[OffGridInTheCity]

I have mine under the house. But is seems popular lately to design/protect against fire - e.g. small metal containers in back yard, sheds, fire-proof boxes, metal cabinets, etc. A couple of folks who did sheds report that 1) good insulation and 2) low power AC (or even fans) can do a pretty good job. @DIY Solar Power with Will Prowse did a small AC in his shed and shared his power numbers.

Check this out - a Tesla battery fire due to overcharging. Fire starts at 3:06 of the video but keep watching, after a few mins, the whole thing goes up like fireworks -

Just to share my own decision process (but not telling anyone else to do this). Part of this (to me) is how extensive you are using the battery bank. Due to long life concerns, I use my 18650 battery bank between 4.0v max and 3.5v min and <200ma/cell for both charge and discharge with an annual average DOD of only 40%. I would consider this 'mild' stress + I have Batrium (e.g. really good monitoring) + I'm confident I won't overcharge or over discharge + all cells are fuse-wired - so I'm OK with them under the house which as you say - provides good mild temps. And LifePo4 has a better reputation than 18650!

However, its up to you as a DIY'er to decide / bear the risk . I'll be interested to see where you come down on this for your situation.