There are huge chemical process is involved in Lead Acid battery’s charging and discharging condition. The diluted sulfuric acid H 2 SO 4 molecules break into two parts when the acid dissolves. It will create positive ions 2H+ and negative ions SO 4 -. As we told before, two electrodes are connected as plates, Anode and Cathode.
A typical lead–acid battery contains a mixture with varying concentrations of water and acid. Sulfuric acid has a higher density than water, which causes the acid formed at the plates during charging to flow downward and collect at the bottom of the battery.
The discharge state is more stable for lead–acid batteries because lead, on the negative electrode, and lead dioxide on the positive are unstable in sulfuric acid. Therefore, the chemical (not electrochemical) decomposition of lead and lead dioxide in sulfuric acid will proceed even without a load between the electrodes.
Figure 4 : Chemical Action During Discharge When a lead-acid battery is discharged, the electrolyte divides into H 2 and SO 4 combine with some of the oxygen that is formed on the positive plate to produce water (H 2 O), and thereby reduces the amount of acid in the electrolyte.
Electrode potentials and cell voltage for a typical flooded lead–acid battery As charging proceeds, the potentials keep gradually increasing until end of charge is reached. At this point, all lead sulfate is converted to lead on the negative electrode and to lead dioxide on the positive; and the charge is complete.
The voltage must be lowered to typically between 2.25 and 2.27 V. A common way to keep lead–acid battery charged is to apply a so-called float charge to 2.15 V. This stage of charging is also called “absorption,” “taper charging,” or trickle charging.
While charging a lead-acid battery, the following points may be kept in mind: The source, by which battery is to be charged must be a DC source. The positive terminal of the battery charger is connected to the positive terminal of battery …