Many times customers allow their lithium ion batteries to become deeply discharged. This is a result of improperly storing the battery from a fully discharged state, extending the duration of storage without performing a maintenance charge, exposing the battery to excessively high temperatures during storage, or any combination of the above. Lithium ion batteries which have been deeply discharged begin to dissolve copper out of the electrodes. This by itself is not a problem (cells can be safely discharged to zero volts), however, the issue is in the subsequent recharge of the battery.
