openinverter forum

Hi All,

I'm new here, so apologies if this is in the wrong place. I am currently in the process of collecting bits to build a DIY powerwall and I was hoping for some advice as the voltages etc are similar to low power ev's.

The inverter I have runs 4 cartridges of lead acid gel batteries. Each pack is 96v nominal and the inverter uses then is a 2s2p configuration to provide a nominal 192v input to the inverter. This might be 192v either side of zero or 192v with, effectively 2 packs in parallel.
Output from the inverter is 8kw at 240v AC.

My aim is to convert the battery packs to li-ion using 18650 cells. The way I worked out the voltages suggests I use 28s6p setup in each cartridge. I therefore need a battery management system that can be used for each cartridge. Eventually I plan to have up to 44 of these cartridges in the system, so needs to be relatively cheap and /or expandable. I am happy to solder stuff together if need be.

Any suggestions? Thanks in advance

What about Stuart Pittaway's diyBMS?

Try searching youtube for 'Adam Welch solar shed' too as he's made some videos about using it.

Doobee, many thanks for the suggestions. I had a quick look at Stuart Pittaways one, looks like its set up for 48v packs, unless I'm missing something?

looks like he's got a new version out, around 4:40 he states up to 64 modules.