This information was obtained from the Panasonic Sealed Lead Acid Batteries Technical Handbook, 1998-1999 It applies to most sealed lead acid batteries.
The battery cycle life is the number of charge, discharge, or rest cycles a cell or battery can provide. Cycle life is usually expressed by the number of cycles available before duration of discharge decreases to a half of the initial value.
Battery cycle life is dependent on the depth of discharge in each cycle. The deeper the discharge is, the shorter the cycle life (smaller number of cycles), providing the same discharge current. The cycle life (number of cycles) of the battery is also related to such factors as the type of the battery, charge method, ambient temperature, and rest period between charge and discharge. Typical cycle-life characteristics of the battery by different charge/discharge conditions are shown by the Figures. This data is typical and tested at a well-equipped laboratory. Cycle times are different for each battery model. Cycle times are also different from this data when using batteries under real conditions.
The service life of a battery is in the trickle use. Usually, the trickle life is the time expressed in years before the dischargeable time of the battery decreases to a half of the initial value.
Trickle life of the battery is largely dependent on the temperature condition of the equipment in which the battery is used, and also related to the type of the battery, charge voltage and discharge current.