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I'm considering adding at least simple cell level BMS to prevent over-voltage charging... because I have a few cells in my pack that are 'drifting' out of balance after a few charge cycles.
I have pack that is 48 x 130ah CALB LiFePO4 large format prismatic cells.
I'm looking for whatever people have found, and used for a while, that can at least stop a charger when the first cell hits some high-voltage limit like 3.70v. It could even be as in-elegant as a signal to a separate relay that would cut power to the charger.
I did a little poking around the web last night and found that MiniBMS is no longer sold standalone... but there are a number of chinese units that look like they MIGHT do the job except they are all intended for 100amp max thru them and I can't really tell if they would work since my Zilla controller could be pulling 1000amps. My charger is just a little 1500 watt Elcon, so 8amps is about all the charge current the pack sees. I don't really even need active shunting, just a HV sense and power off would be fine.
I found things like this:
https://www.ebay.com/itm/4S-12V-100...ry-Cell-BMS-Protection-PCB-Board/152854161901
but they look like they are intended purely for 12v (4 cell) packs
Can any of the EE types here tell if these units would be capable of watching 4 cells at a time, and sending a signal I could use to trigger a relay if any single cell hits the high-voltage limit? I can't tell if this type of BMS could be used just to watch voltage and not worry about balance shunting or passing full current load.
I am just looking for the cheapest dumbest way to watch 48 cells in series, and turn off the charger as soon as the first one hits 3.70v
I have pack that is 48 x 130ah CALB LiFePO4 large format prismatic cells.
I'm looking for whatever people have found, and used for a while, that can at least stop a charger when the first cell hits some high-voltage limit like 3.70v. It could even be as in-elegant as a signal to a separate relay that would cut power to the charger.
I did a little poking around the web last night and found that MiniBMS is no longer sold standalone... but there are a number of chinese units that look like they MIGHT do the job except they are all intended for 100amp max thru them and I can't really tell if they would work since my Zilla controller could be pulling 1000amps. My charger is just a little 1500 watt Elcon, so 8amps is about all the charge current the pack sees. I don't really even need active shunting, just a HV sense and power off would be fine.
I found things like this:
https://www.ebay.com/itm/4S-12V-100...ry-Cell-BMS-Protection-PCB-Board/152854161901
but they look like they are intended purely for 12v (4 cell) packs
Can any of the EE types here tell if these units would be capable of watching 4 cells at a time, and sending a signal I could use to trigger a relay if any single cell hits the high-voltage limit? I can't tell if this type of BMS could be used just to watch voltage and not worry about balance shunting or passing full current load.
I am just looking for the cheapest dumbest way to watch 48 cells in series, and turn off the charger as soon as the first one hits 3.70v