Cycle Life Testing
The cycling current is 1500mA for AA and 500mA for AAA cells. Charge and discharge currents are always identical.
Charging uses 0dV termination, discharge cuts off at 0.9 V (measured under load).
Internal impedance is measured once every 10 cycles in charged state using internal resistance meters.
From the first 40 values the cell’s initial capacity is calculated. Then the cell is cycled until its capacity falls below 80%.
At this point the average capacity is calculated from values measured throughout the cell’s lifetime.
Also the score points are calculated (Score = Cycles * Capacity / 1000) which represent the total Amp-hours delivered by the cell throughout its lifespan.
For graphing purposes the cell is cycled yet another 80%, e.g. until 64% of its initial capacity.