Suggestion improve Cell runaway function

[red0909]

at the moment the 4.9 all in one module balances only one cell after an other, but it should balance all cells at same time if they are over the set voltage and deviation.

[stuartpittaway]

The v4.9 board should balance any cell once it goes over the limit specified in "Bypass threshold voltage (mV)".

The run away cell function, is completely separate and tries to find high cell voltages before they reach this level.

[red0909]

this bypass setting does not work if dynamic charge voltage is used.
the cell voltages desnt go over the set bypass voltage because of the charging algorithm. the cell runaway does work but it balances only one cell. this is not enough if u have two cells low and 14 high.
so a change is needed to balance all cells those who are over the set start voltage and deviation

so in my case the bypass voltage is on 3,52v and the charge voltage on 3,5v (cvl)
i if set bypass lower than 3,5v it will balance constantly when the battery is full and balanced

dont get confused the cvl of 57V is 56V in sunny island, it charges always 1v lower than transmitted(i dont know why)

[stuartpittaway]

Ok, the whole purpose of the dynamic charge function is to ensure that a cell never goes over the limits - therefore, you never need to shutdown and lose power.

The run away cell logic would need some more work to handle multiple cells - it was just designed to spot a single high cell and bring it back down.

[red0909]

this would be a nice feature if you can change this.
so the cells can balance over time with the new 4.9 module.
now they are not balancing if dynamic charge is activated.

[Bingo2023]

I used last summer the Victron CAN & Victron HW and it worked great.

here are the settings check especial the red marked.
Also make sure that the Charger Voltage is little higher to reach that levels.
I dont remember the bypass voltage exactly but try 3,65V +/- little 2-5mV - I was able to find good settings.
Below is a datasheet from my CATL cells, they propose settings for the BMS (1st Level 3,8V 2nd 4,0V).
Check your datasheet, but maybe 3,5V is too low. The higher the more they tend to run away. If you go like 3,5V they are all very same level -> all cells will balance at same time and each cycle.

[red0909]

3,5V is optimal its enough for balancing, but your method does not work for me look the image above
the bypass voltage is never reached and if its reached, if i set it at or below charge voltage, it will constantly burn energy in summertime.
this is not designed for that constant bypass, but the runaway function stops burn energy if deviation is under the set value so it will not burn energy constantly in summer, it just need an update to balance all cells those over the limits.