Imbalance on one Li battery in bank of 5. Inaccurate Voltage meter?

DIY
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We have 5 pcs of 200 Ah Li 24 Volt. And a LYNX Smart BMS. Normally charged by MPPTs. Se picture.

One of the batteries “Epsilon” is showing a lower Voltage (About 0.1 V). It does not matter to move it. Still it is that specific battery. So not cabling issue.

And it shows “Balancing/Imbalanced” even if it looks pretty balanced to me.

Have tried to increase charge time - but it seems only way is to disconnect all other batteries and just charge the imbalanced. Then it will go balanced for a few months.

I have a theory that this battery want a (slight) higher voltage - but the other batteries prevent the BMS to supply this.

Maybe bad Voltage measurement (should be same all over - right?)

Any ideas?

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2

@SailYachtSowilo I suspect there is a bad cell maybe and the bms expects the voltage to reach 3.55V for cells to balance which it fails to reach as you can see in the mav cell voltage for that battery.