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Building some 2P 16S 48VDC LiFePo4 from 100Ah 3.2's using 16S Overkill BMS

Snowboater

Off grid - in the sun on The High Road to Taos
Joined
Jan 12, 2021
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I love the robustness of the "doublewide" battery in one of Will's vids as he's building a 12V battery with bus bars, but he didn't exactly address the BMS issue. No offense Will - you're the best dude out there. I've learned a ton. Thank you.

Will mentions quickly toward the end "if you connect your inverter and 4 charge controllers." My contention is by bus bar-ing the 4 cells together in parallel all four BMS's will produce the same reading for all four cells in the group. Thus, we have four BMS's doing exactly the same thing (?). All issues of control aside, would we be able to multiply the potential throughput on the BMS's to overcome the crappy little wires? A single100A BMS can become 4 BMS's that can move 400A?

I'm seeking advice on balancing cells tied in parallel.

Question is since each "cell" in the battery is double wide when I connect the BMS it's going to be controlling two cells at once. Not sure that this qualifies as actually controlling each individual cell (yes we're still controlling 16 cells at 3.2V, but each cell is a group tied in double wide). I'd actually like to take it a step further and go 4P, but the BMS claims a 100A in/out. Therefore to go from "dead" to charged would require 8 hours - since I don't figure to be totally dead and sun for 8 hours in New Mexico isn't a problem (most of the time) - I might be alright. But then the BMS would be controlling 4 cells in parallel by 16S. Do the sets of 4 cells balance themselves? Also I'd only be able to pull 40A @ 120VAC (only ;-) - Although some might consider this system unbalanced consider I'm starting with 4 batteries (either 2x's or 4x's - same limitation 160A max draw).
 
You may want to review this:
Looks like if I top balance similar cells and tie them in parallel pairs there's little chance that they'll go out of balance outside of cell failure. Either way, the system will at least be functioning.

Thanx for the info.
 
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