Batrium Cell 1 Lower Than The Rest

[Steve2649]

Hello,

I have a Batrium 14S Watchmon with Longmons. The first cell is always lower than the rest of the pack. Even after top balancing, it depletes the fastest. Is this because it's the last pack in the series that goes to negative side of shunt?

 

[MurphyGuy]

If the cell depletes faster than the rest AND charges faster than the rest, its because the cell's capacity is less than the other cells.

However, if it charges at the same basic rate, but always seems to be lower regardless, then its probably because the cell has a bit of internal self discharge that is taxing it.

I have a 25kWh battery bank of lithium ion cells.. 14 series, 8 in parallel.. one of them (#12) has a slightly higher self discharge than the rest so it tends to always be at a lower voltage.
But when I charge and discharge the battery bank, that one cell will go up and down with the rest evenly.. only after several weeks will I notice it is lower than the rest.

To solve the problem, I just hook up a small hobby charger to that one cell and pump some juice into it to bring it in line with the others. This only needs to be done two or three times a year.

 

[Steve2649]

If the cell depletes faster than the rest AND charges faster than the rest, its because the cell's capacity is less than the other cells.

However, if it charges at the same basic rate, but always seems to be lower regardless, then its probably because the cell has a bit of internal self discharge that is taxing it.

I have a 25kWh battery bank of lithium ion cells.. 14 series, 8 in parallel.. one of them (#12) has a slightly higher self discharge than the rest so it tends to always be at a lower voltage.
But when I charge and discharge the battery bank, that one cell will go up and down with the rest evenly.. only after several weeks will I notice it is lower than the rest.

To solve the problem, I just hook up a small hobby charger to that one cell and pump some juice into it to bring it in line with the others. This only needs to be done two or three times a year.

Thanks Murphy, I'll try topping it off and see how it works out. I suspect if it continues to drain faster, might be a bad connection somewhere.

 

[Bob B]

You could move that cell to a different location and see if the problem stays with the cell.