16S lifepo4 uneven voltages

Troubleshooting
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1

I have a setup with 16pc Eve LF280K and cellmate k9.
Now with sunny days, my battery is full. But I see a strange behaviour at the voltages.

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All uneven cells are at 3.5V, the even cells are between 3.51 and 3.53.

Just curious why this is.

John

2

Hi John,

Thank you for adopting BMI, I’ve been able to take a look at your system from here and have a few things I’d like you to check.

  • I can see that your final ramped charge target is 10A, I suggest moving to Normal/Limited mode, and changing the limited value to something like 1A. This allows the balancing to keep up with the charger and even everything out nicely.
  • Your system is going into thermal relief mode during charging due to misconfigured voltage thresholds. This explains the odd-even pattern you are seeing, as balance cycles start on the even cells. In short your system is spending a long time balancing and the K9 is getting too hot and telling the charger to stop.
  • To fix the above, the easiest way is to hit the “Default” button on the Control > Charging, Control > Remote and Hardware > CellMon pages.
  • If you wish to keep your current setup, make sure:
    • Your bypass voltage is 50mV above your charge target, not below
    • Re-enable the charge cutout threshold voltage and set it to your charge target.
    • Your resume voltage is a fair bit below your charge cutout voltage

A new, healthy system should be doing <50mAh of balancing a day, yours is doing as much as 1200mAh

Please let me know if you need me to clarify anything above, I’m more than happy to explain further

3

Thanks.
I am not able to make changes on short notice.
This weekend I will very and adjust as recommended and let you know.

John

1 Like
4

James, I have just set the values to the default settings as recommended. Do uiu have any recommendations on the Victron Assistant settings, based on the default Batrium settings?