The lead-acid battery mainly uses two types of charging methods namely the constant voltage charging and constant current charging. It is the most common method of charging the lead acid battery. It reduces the charging time and increases the capacity up to 20%. But this method reduces the efficiency by approximately 10%.
Definition: The lead acid battery which uses sponge lead and lead peroxide for the conversion of the chemical energy into electrical power, such type of battery is called a lead acid battery. The lead acid battery is most commonly used in the power stations and substations because it has higher cell voltage and lower cost.
Under the right temperature and with sufficient charge current, lead acid provides high charge efficiently. The exception is charging at 40°C (104°F) and low current, as Figure 4 demonstrates. In respect of high efficiency, lead acid shares this fine attribute with Li-ion that is closer to 99%.
The battery should not, therefore, be discharged below this voltage. In between the fully discharged and charged states, a lead acid battery will experience a gradual reduction in the voltage. Voltage level is commonly used to indicate a battery's state of charge.
This mode works well for installations that do not draw a load when on standby. Lead acid batteries must always be stored in a charged state. A topping charge should be applied every 6 months to prevent the voltage from dropping below 2.05V/cell and causing the battery to sulfate. With AGM, these requirements can be relaxed.
If the battery is left at low states of charge for extended periods of time, large lead sulfate crystals can grow, which permanently reduces battery capacity. These larger crystals are unlike the typical porous structure of the lead electrode, and are difficult to convert back into lead. Voltage of lead acid battery upon charging.