I have the BYD premium LVS12 (3 modules of 4kwh) and I always get the warning everytime the BYD battery reaches 100%, going away after some minutes even and battery fully charged:
Can you see the cell number with highest voltage?
@ 60-70% SOC is this the same cell?
Seems to me the balancer isnât working, resulting in one cell more charged than the others.
It can also be a bad cell but you first have to top balance (within a few mV) before you can check.
A high cell voltage warning when BYD batteries are nearly full is somewhat normal, as long as its a warning and not an error.
What helps is setting the DVCC Max Charge Voltage to 57.6V.
In BYD manual nothing about how to adjust balancing start voltage.
You canât edit the BYD parameters.
But you can set DVCC values on Victron side.
Happy to chosen a DIY solution with active balancer.
Did somewhere read BYD does use a passive balancer with only 100mA.
Passive balancer for LiFePO4, that explains a lot,âŚ
Somehow that seems unlikely.
In the manual for their LVL Premium battery thereâs this in the âError codesâ section:
Blue LED is flashing nine times: BIC balance failure
Yes, that was what I also found.
And this old post:
BYDâs work well. They adjust their CVL based on charge level.
Unless something is broken, standard settings should be fine if provided sufficient opportunity to charge.
Like any battery if it isnât optimally sized, and is unable to properly charge regularly, there will be problems.
But with only 100mA passive balancer, you will get cell runaway.
Would open the casing to see if there is room for a NEEY balancer.
The pack will drop the CVL when thresholds are hit. That should be sufficient to prevent anything happening. Their systems work fine and are enormously popular. I only see them mutter when heavily discharged and not fully charged for some time. They sort themselves out quite quickly once allowed to charge.
Yes, but without proper top balance, you will get the error every cycle.
And it seems the internal balancer isnât capable to balance the cells.
There are many, many installs that donât support that assertion.
Have my own as well, cycled properly, not always charged fully each day, no issues.
Two warnings (not alarms) this year, and it had not been properly charged for an extended period. One decent cycle on âkeep batteries chargedâ sorted them out.
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Problem without proper top balancing is that you lose capacity, and that it get worse with every cycle.