Maintenance free wet-cell (Ca-Ca) batteries can be stored without loosing their charge for 6 months while hybrid batteries can be stored safely for 3 months. Batteries will suffer damage if stored in a discharged state. All batteries should be kept in a cool and dry area and wet-cell batteries in particular should be stored in an upright position. Do not stack batteries directly on top of each other, unless with a separating medium such as polystyrene sheet. Top of the battery cases should be clean at all times.
The batteries should follow First In First Out (FIFO) rule. The stack should contain ex-factory and storage date on it. For example, the battery code 280421 specifies that respective battery was produced in second production line, in the year 2008, month April, day 21.
Recharging guidelines for calcium wet-cell (Ca-Ca) batteries:

  1. Once in every 6 months if storage temperature is below 27°C.
  2. Once in every 3 months if storage temperature is above 27°C.
  3. Recharging is necessary if the open-circuit voltage drops below 12.4 volts. This method can be applied as an alternative to the first and second options above.
  4. Recharging hybrid wet-cell batteries takes about half the time.  

ATTENTION: During charging process, it is very important to avoid overflowing of acid and high temperatures over 52°C. If temperature does rise, either decrease the charging current or stop charging all together until battery temperature returns to a normal level. High charging temperatures will damage your battery and shorten its life.