Question about batteries below the minimum discharge voltage

I recently acquired three older Blue Robotics 14.8V 18Ah batteries that have been sitting on a shelf for an indeterminate period of time. Two of the batteries are above 15V, but one battery is below 10V (see attached photo). Is the battery at < 10V salvageable, or should I dispose of it?


Hi @oneironautics,

That depends on why it’s at that voltage level.

If the cells have mismatched voltages, or it’s at all puffy (before or during charging) then it’s not worth the risk and should be disposed of.

If, however, the cells are still well-balanced then from your picture it’s only marginally below the 2.5V/cell point, in which case it’s likely still worth attempting a (slow) balance charge to see whether it’s able to be recovered. If that isn’t effective but also doesn’t have any obvious detriment you could potentially try reconditioning, but that’s not something we have experience with, and it would likely have a reduced capacity even if it works to return the battery to a usable level of charge.