The balancing process never stops because the cooling is too good?

I have two different systems with the same strange behaviour I recently discovered.
When the balancing process of the passive balancer on the Blockmons is running and the cooling in our battery packs is active, the Blockmon will not stop the balancing process (at least I had it running for a few hours for testing). It seems that when the 2 amps balancing current is used, the Blockmon no longer checks the cell voltage and continues to burn energy. The end result is a disastrously unbalanced battery.

As a workaround for this problem, I implemented a bit of logic that disables the fans for 1 minute every 5 minutes. So that 1 minute allows the blockmon to “overheat” and therefore shuts down the balancer.
I think this is a pretty serious problem, which may or may not lead to undervoltage in the cells.
Maybe there is a config which i missed somewhere, i encountered that problem now in 2 different systems.

Here is also a picture showing the result (the cells which are low now, had the problem before, the ones who are balancing in that photo have the problem right now):

Thank you very much,

I have a similar issues with watchmon core and cellmate k9. It gets stuck on bypass and I have to reset the bms in order for it to stop. Haven’t had this issue ever before nor have I updated my firmware lately .

Hello , have you found a solution for this problem yet?

No. I just turn the fan off after a few minutes to give the balancer boards a chance to overheat. Not a clean solution.
Since this is reproducible, it could be tested by Batrium themselves. They just need to put a big fan next to a Blockmon and charge the battery…

Hello h4ckst0ck,

From what we could see from your photo, it’s quite normal if the cell reaches its bypass voltage of 3.5V to remain in bypass until all other remaining cells achieve the goal, which is currently sitting at 3.3V. Please know this is done by design.

Might be best if you could send your manual extract report. You can email it to so we can investigate further. SUPPORT - How to create a Manual Extract Report

You can set the balancing board temperature to 65° but without your extract, we cannot be certain.

Please know that you should be charging all your cells to get up to 3.5V. We are uncertain why you want some at 3.5V to switch off while some are still at 3.3V.

If you are wanting to stop the charge, at 3.5V before balancing occurs, this can be adjusted on the charging control rule screen. Control Logic - Charging Settings

1 Like

I think I have expressed myself incomprehensibly, if one could interpret the text so. The battery was perfectly balanced. With a difference of about 10mV at about 3.50 V per cell. After I activated the ventilation, the balancers do not stop balancing even if the cell voltage has long since dropped below 3.5 V again. The picture only shows the result of charging the next day when the same problem occurred again. Only this time you can see the effect of the problem.
I am on vacation right now and will do the extraction of the data at the beginning of August.


There could be a couple of things we may need to consider.

Know that if you are monitoring this remotely, the display does not refresh as frequently as the BlockMons themselves. It may show it’s balancing but that may not be the case as this field gets updated less frequently as mentioned.

You may also need to look at the individual cell bypass session mAh. You might find that this is not increasing as this is not balancing. When the BlockMons reach their threshold, they stop balancing as soon as it’s below the configured voltage threshold.

From the WatchMon supervisor, the cell voltage is only shown as 2 decimal places. However, the BlockMon itself has additional precision and it’s burning down to be below the threshold.

Can you also let us know if you are using the extra balancing rule of auto level?

These questions can be answered once we have a look at your configuration and you have sent the manual extract report.

1 Like