The table below compares the characteristics of the six most commonly used rechargeable battery systems in terms of energy density, cycle life, exercise requirements and cost. The figures are based on typical ratings of commercially available batteries at the time this was written. 30 days 90 days 3-6 months 9 not req. Failing to apply periodic full discharge cycles may reduce the cycle life by a factor of three. 2 Cycle life is based on the depth of discharge.
Shallow discharge provides more cycles than deep discharges.
The discharge is highest after the first 24h, then tapers off. Self-discharge increases with higher temperature. 5 1.25V is the official cell voltage rating, 1.2V is now also commonly used. There is no difference between the cells. 6 2.5-3.0 volts depending on positive electrode used.