EMP/CME Battery Choice

[Devin82m]

Hey everyone, I was wondering if any of you have taken into account EMP and or CME protection?

I've done a decent bit of study on the subject, my conclusion is that LiFePO4 batteries are great, but their largest weakness is the BMS. So I had to rule out Battle Born batteries sadly since they are so proprietary and their batteries are sealed units. They also do not sell their BMS separately (I asked) nor do they ever plan on making a self service model at least in regards to the BMS.

Therefore I am down to SOK batteries (I know there are other servicable brands out there) because they are servicable and they sell their BMS separately. Or I may build my own pack out of Fortune cells and Overkill Solar BMS.

So between those two options which would any of you suggest and why?

Also, I plan on building a small 24v 100 Ah system, should I go with two BMSs (two 12v) or one 24v BMS? Why?

 

[snoobler]

No.

DIY: cost and value.
1 24V BMS. 2X 12V bms only manage 4 cells each and permit more imbalance than managing all 8 cells together.

 

[Bob B]

My opinion is that it depends on what cells you are using. If the cells are well matched, the configuration is more forgiving.

I have 8 190 ah cells in a 2P4S configuration using 1 Chargery BMS .... it is working fine. My cells remain within 20 mv across the entire charge / discharge range. I now have the BMS set so that it isn't even trying to balance. I got lucky with these cells because I ordered them when I didn't really know much about this chemistry.

From what I have seen there is a lot more deviation .... or what some call "runners" .... in the 280 ah cells. Using those cells it would probably be best to use 2 separate packs.

 

[Devin82m]

OK, thanks for the info guys. Yeah I will probably use 100 ah cells and the Fortune seem to be the best out there. I will probably go with one 24v BMS, that is a good point about less deviation.