Battery reconditioning is a maintenance process used to increase the usable battery pack capacity and extends its service life. Battery reconditioning is not a one-time event. If performed once and never repeated, the benefits of battery reconditioning will be short lived. Proper battery reconditioning as a recurring maintenance process can significantly extend the service life of the hybrid battery pack. For nickel-based batteries (NiMh or NiCd), the battery performance will decline mostly because of crystalline formation. It isn’t a memory issue, but it is caused by partial discharging and, sometimes, poor charging.NiMH modules undergo shallow depth-of-discharge (less than 10%) because they are used for power assist, not electric drive. Unused electrode material develops a resistive barrier that reduces amp hour (Ah) capacity. This reversible failure mode (“memory effect”) causes modules to become out-of-balance with neighboring modules, especially those that are near the pack center. Out-of-balance modules can undergo cell voltage reversal during discharge, which results in permanent damage.