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Heltec 4S LiFEPO4 battery active balancer connection.

hondaman82

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Jan 13, 2021
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Hi everyone, hope your day goes well, I just got a Heltec 4S 5S 6S 5A Capacitor Active Equalizer Balancer Lifepo4 for my DIY 12V 272 AH 4 cells battery back with Daly BMS. The BMS alone did not balance the cells well for me so I have to top balance the cell once in while. I think the active balancer may help keeping the voltage as close to each cell as possible.
May I ask, when connecting the Active balancer to the cell terminal is it OK to leave them connected all the time while charge or discharge the battery?
I read someone comment on Amazon to disconnect the sense cable from the balancer board when discharge and hook it back when charging, I think it is very inconvenient to do that as my battery and AC inverter are in an enclosed box. thank you for your help,,,cheers!
 
I think the issue is if you use only the BMS for SOC and a separate active balancer. The BMS may over report.
 
I think the issue is if you use only the BMS for SOC and a separate active balancer. The BMS may over report.
Interesting thought. Is this because the balancing currents between the cells are not flowing through the BMS shunt and therefor it cannot accurately report the remaining SOC ?
 
That’d be my guess, the BMS knows what it does for balancing but can’t track the Haltec, just a guess.
 
I'm looking at one of these 5A versions for my 560Ah 13.2V pack (pairs of 280Ah are wired in parallel with 1 BMS). My C rates are very low. RV application. Highest load is 125A for air conditioner. That happens 2 X / year for a few hours. Charging is normally solar - up to 45A. Normal loads are 5 to 15A.
Anyhow, I store the RV most of the time. Can I put a switch on the negative lead to disable in storage, so it doesn't deplete the battery while stored for a few months?
My cells don't get far out of balance. But the passive balancing doesn't work worth beans :) no surprise for such large cell capacities.
Thank you,
Doug
 
I would sooner just pull the harness off the board. Otherwise there should be a provision for a switch on the board itself. Look for the "RUN" connection next to the harness. Remove the bond and add a switch.
 
Tim,
Good point. but then again, when you plug the harness in, there is no guarantee all connections are made exactly at the same time.

Doug
 
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