Battery Storage
It is recognized that LCB valve regulated batteries have excellent charge retention characteristics. That is, their self - discharge rate is low and is typically less than 3% per month at 25°C. the self discharge rate will vary as a function of ambient storage temperature. Following chart shows the relationship between storage times at various temperature and the remaining capacity.



Supplementary Charge Advice

Storage Temperature
Life
Below 20°C(68°F)
9 months
21°C(70°F) to 30°C(86°F)
6months
31°C(88°F) to 40°C(104°F)
3months
41°C(106°F) to 50°C(122°F)
1.5 month
Storage Temperature: Below 20°C(68°F)
Life: 9 months
Storage Temperature: 21°C(70°F) to 30°C(86°F)
Life: 6months
Storage Temperature: 31°C(88°F) to 40°C(104°F)
Life: 3months
Storage Temperature: 41°C(106°F) to 50°C(122°F)
Life: 1.5 month


In discharging a battery, lead sulphate (sulphation) is formed. If the battery is recharged as soon as discharging is completed then the lead suIphate is converted to active material. However on self discharge the lead sulphate that is formed may become refractory. That is it cannot be reconverted. The lower the voltage that a battery is allowed to fall to under self discharge the more likely it is that the sulphate formation will not be able to be reversed and the battery damaged beyond recovery.


Recharging a Self Discharging Battery

When it is necessary to give a self discharged battery a “top up” charge the following procedures should be observed.
1. Ensure the OCV of the battery is greater than 2 vpc. If the voltage is lower than 2 vpc please refer the problem to LCB before attempting to recharge.

2. Constant voltage charging is recommended.

Battery Age
Life
Less than 6 months from manufacture or previous top up charge
Maximum of 20 hours at a constant voltage of 14.4V
Up to 12 months after manufacturer or previous top up charge
Maximum of 24 hours at a constant voltageof 14.4V
 
Less than 6 months (As above)
 
Maximum of 6 hours at a constant current of 0.1C Amps
Up to 12 months (As above)
 
Maximum of 6 hours at a constant current of 0.1C Amps
Battery Age: Less than 6 months from manufacture or previous top up charge
Life: Maximum of 20 hours at a constant voltage of 14.4V
Battery Age: Up to 12 months after manufacturer or previous top up charge
Life: Maximum of 24 hours at a constant voltageof 14.4V
Battery Age: Less than 6 months (As above)
Life: Maximum of 6 hours at a constant current of 0.1C Amps
Battery Age: Up to 12 months (As above)
Life: Maximum of 6 hours at a constant current of 0.1C Amps

Effect of Temperature on Battery Capacity
The nominal battery capacity is based on the temperature of 25°C. Above this temperature the capacity increases marginally but it must be noted that the working battery should be kept within the temperature design limitations of the product.

Below 25°C the capacity decreases. This decrease in capacity becomes large at temperatures below 0°C and in heavy discharge rates. The graph below illustrates the situation and the decrease in capacity with the decrease in operating temperature must be taken into capacity design calculations in applications where the operating temperature of the system is below 20°C.