Battery Charging

General rule for charging NiCd & NiMH batteries

Assuming the battery is in a fully discharged state (1V per cell), calculate the charge time in Hours for a Nickel Cadmium (NiCd) or Nickel Metal Hydride (NiMH) battery pack using the following formula:

Charge Time in Hours =

Capacity (C) rating of battery in (mA) x 1.4

Output current in (mA)

In general, for standard charge you need to put up to 140% energy in to obtain 100% energy out of your batteries.
For fast & rapid charge techniques this figure of 1.4 (140%) may need to be reduced by up to 15%. This is dependant on your charging parameters and charger termination method.