Hi
thanks for the suggestion. Do you have any technocal material for that ? I would be interesting how they daisy chain the BMS.
In praticle I also believe it is fine, the only limitation would be adiditonal software to hook up all serial BMS in the configuration.
How about the balancing, any suggustion for such solution?
thanks in advance
I wrote a post about the LG RESU 10H 400Vdc battery pack with pics ... but I only translated and summarized it from Hungarian
I am not the author. But I think the 3 x 48V BMS does not sync or balance in the RESU. So there is no master BMS over the three small 48V BMS
I am currently in the process of installing an SMA SunnyBoy 7.6 KW (Grid-Tie split phase 120/240v) system, with 30 Qcell 320 watt panels. I am awaiting my permit to finish install and to get the power company to reprogram my meter to read backwards. Right now I have 15 panels on my roof "testing...
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I was also thinking this problem when I saw the new Tesla Model 3 LFP battery disassembled:
First I tough this are the 310Ah CATL cells we can buy from china. But it seems the height is lower and the length is bigger.
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That is like a 104s pack.
So if I would start this project (and I am not Tesla to make my own very expensive BMS) then I would start with
- a perfect top balance for all cells
- a BMS for every 48V pack like JK Heltec.
- serial connection from every BMS to RasPi
- main highVdc relay controlled by RasPi. So the RasPi is the master BMS that shuts down the pack if needed.
And lets see how long it takes for the big 48V pack's Volts to got unbalanced.
(and of course use battery only in the 10-90% SoC range, because there is no balancing between the 48V packs)
Another "stupid" idea :
overlapping balancing.
The Heltec BMS is 24s (and 48V is 16s). So you connect
- 1st to 1-24 cells
- 2nd to 17-40 cells
... so you have 8 cells overlap.
This cells then transfer power between 48V packs.