When lead dioxide (PbO2) and lead (Pb) are immersed in dilute sulfuric acid (fluid) (dilute sulfuric acid: 38%, specific gravity: 1.280), lead (Pb), a metal with large ionic drift, acts as the anode and lead dioxide (PbO2), where ionic drift is small, acts as the cathode and they come together to create a chemical reaction, giving off an electromotive force (EMF) of approximately 2V.
 
 
Discharge, depending on the electrical parts used in cars, refers to the conversion of chemical energy into electrical energy. The cathode (PbO2) and anode (Pb) terminals convert to PbSO4 and the dilute sulfuric acid (fluid) react with the active material on the grids and change to water, which has a lower specific gravity.
 
Cathode: PbO2 a PbSO4
Anode: Pb a PbSO4
Battery Fluid: Dilute sulfuric acid (specific gravity: 1.280) a Water
 
Self-discharge refers to the phenomenon of natural reduction in voltage, specific gravity and electrical energy after a certain amount of time without the influence of an external circuit.
 
Use of a charger/discharger (for cars) converts electrical energy back into chemical energy. The electrical energy converts the PbSO4 at the cathode and anode into PbO2 and Pb, respectively, and reacts with the active material on the grids to raise the specific gravity to the norm and emits an electromotive force.
 
Cathode: PbSO4 a PbO2
Anode: PbSO4 a Pb
Fluid: Water a Dilute sulfuric acid (specific gravity: 1.280)
 
Constant Currents: This method of charging applies a constant current (A) to raise the voltage of the battery. Pay careful attention to the charging current and the charging time to prevent overcharging of the battery. After charging is complete, make sure to turn off the switch.

Constant Voltage: This method of charging generates a constant voltage from the charger to gradually reduce the current that enters the battery throughout the time of the charging process. Unlike the method of applying constant currents, there is no need to worry about charging currents and charging time. This method is most appropriate for MF batteries.

Constant Currents/Constant Voltage: In this method, a constant current is applied during the initial charging period and then a constant voltage is applied during the latter part of the charging period. This method is used to minimize any damage that can occur to the battery during the charging. This charging method is most commonly used for Deep Cycle batteries.