Different usage applications will use different methods for evaluating a battery’s performance. Using a 20 hour rate or the 10 hour rate, you can use 0.05CA or 0.1CA to discharge the battery until the battery reaches a terminal voltage of 10.25 volts. You can then calculate the amp hours to see if the battery fits the specifications or not. For a 5 minutes rate, such as the HC1221W, you can use a 21 watts/cell discharge till the terminal voltage reaches a terminal voltage of 9.6 volts and then measure the discharge time to see if it meets the final specifications or not

1 – Batteries for UPS or emergency lighting systems are always in charging condition. It is necessary to buy higher quality batteries to avoid overcharging damage. Swelling batteries are usually happened due to overcharging and the problem could be the charging equipment system. In general, if charging current does not reduce for a long period, batteries will lack of water and swell due to overload. However, other reasons like bad quality and internal components corroding too fast will also cause the battery charging connection defectively. And charging batteries overly result in overcharging problem simultaneously.
2 – Batteries for UPS or emergency light systems will result in overdischarging problem due to overloaded if the power is shut off or batteries not being charged for a long period.
3 – Overcharging of automobile battery： First, check the charging voltage and current of Regulator. If the standard voltage is 14.4V and the measure voltage is greater than 15V, it indicates that batteries are getting overcharging easily
＊Conditions of overcharging condition are ：
(1)Abnormally high electrolyte Specific Gravity
(2)Electrolyte turbidity
(3)Plate corrosion
(4)Water reduces much faster than before
＊Condition of over-discharging is：
Abnormally low electrolyte Specific Gravity

When charging a battery with overcurrent, the charging time will be shortened. However, a battery will be heated easily under overcurrent and gases will be generated inside to cause the danger of thermal runaway. Therefore, the maximum charging current is 0.3CA.

(1)Do not use new and old (over one month after manufacture) batteries together.
(2)Do not connect batteries of different brands, different capacity, and different voltage in series.
(3)Do not charge and discharge batteries in parallel if the voltage difference inside each loop is too large.

“Cycle Use” – direct power source:It can provide the power supply to power tools, portable electronic products. It can also be used for cycling charging and discharging usage such as electronics motorbike or vacuum cleaner.”Standby Use” – back up power: Mainly used for emergency power to avoid future damage that may be caused by a sudden power outage.