Do-It-Yourself BMS

[malabarmcgyver]

I have five LiFePO4 battery banks that I am considering, so having a BMS for each one seemed daunting financially. I found this DIY site and I have jumped in and ordered boards and components. It solves my battery charging cutoff and restart issue without breaking the bank. I am not much of a programmer, but it seems pretty laid out for me. I will let you know how it goes.

See the project here: https://community.openenergymonitor.org/t/diybms-v4

[Ampster]

I don't know what your batteries are. If any chance they are similarly rated prismatics it may be worth putting them in buddy pairs and having one BMS on a single pack. Much easier to manage.
EDIT:
I checked the link and it looks like that hardware is for a chemistry that is different than LFP. If you charge LFP to 4.09 volts you will cook them in no time.

[malabarmcgyver]

The BMS in the link is user defined in the settings and the primary reason that headed down that path because I want to stay below 90% SOC. If you watch the intro video, there is a config screen with over-voltage, under-voltage, individual cell voltage, etc. Also, I have separate banks on a boat intentionally for redundancy. I considered combining in a 2P16S, but thought better of it. I have always kept port and starboard banks completely separated and I think it is best to continue. Thanks for the input.

[Ampster]

Thanks, that makes sense especially on a catamaran where you want to keep the weight in the hulls balanced. It took me a while to remember our earlier conversation. I was a keel boat sailor for many years.

[HollySprings]

@malabarmcgyver, I see you have the boards up and running. Just curious, did you order PCBs and place components or go through a service like JLCPCB SMT Assembly? I'm hung up on the BOM and CPL files (can't upload to JLC assembly). I really like what's going on with George Boudreau's mods since my implementation is Leaf modules.