Storage

Observe the following conditions when batteries need to be stored.
(a) Ambient Temperature: 5°F to 104°F (-15°C to 40°C).
(b) Relative Humidity: 25% to 85%.
(c) Storage Place: Free from vibration, dust, direct sunlight, and moisture.

(2) Self Discharge and Refresh Charge

During storage, batteries gradually lose their capacity due to self discharge. As a result, the capacity after storage is lower than the initial capacity. For the recovery of capacity, repeat charge/dischargeseveral times for the battery in cycle use. For batteries in trickle use, continue charging the battery as loaded in the equipment for 48 to 72 hours.

(3) Refresh Charge (Auxiliary Charge)

When it is unavoidable to store the battery for three months or longer, periodically recharge the battery at the intervals recommended in the table below depending on ambient temperature. Avoid storing the battery for more than 12 months.

The result of testing the residual capacity of the battery which, after fully charged, has been left standing in the open-circuit state for a specific period at a specific ambient temperature is shown
in the figure below.

Residual Capacity Test Results

(5) Open Circuit Voltage vs. Residual Capacity

Residual capacity of the battery can be roughly estimated by measuring the open circuit voltage as shown in the figure below.

Open Circuit Voltage vs. Residual Capacity