Lead-acid battery voltage capacity discharge diagram

What are the capacity parameters of lead-acid batteries?

Various capacity parameters of lead-acid batteries are: energy density is 60-75 Wh/l, specific energy is 30-40 Wh/Kg, charge/discharge efficiency is 50-92%, specific power is 180 W/kg, self discharge rate is 3-20%/month, cycle durability is 500-800 cycles and nominal cell voltage is 2.105 V . [...]

How does specific gravity affect a lead-acid battery?

The specific gravity decreases as the battery discharges and increases to its normal, original value as it is charged. Since specific gravity of a lead-acid battery decreases proportionally during discharge, the value of specific gravity at any given time is an approximate indication of the battery’s state of charge.

What happens when a lead-acid battery is discharged?

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.

What is the voltage of a lead-acid cell?

The voltage of a typical single lead-acid cell is ∼ 2 V. As the battery discharges, lead sulfate (PbSO 4) is deposited on each electrode, reducing the area available for the reactions. Near the fully discharged state (see Figure 3), cell voltage drops, and internal resistance increases.

How do you know if a lead-acid battery is fully charged?

The following are the indications which show whether the given lead-acid battery is fully charged or not. Voltage : During charging, the terminal voltage of a lead-acid cell When the terminal voltage of lead-acid battery rises to 2.5 V per cell, the battery is considered to be fully charged.

How do you charge a lead-acid battery?

For most lead-acid battery subsystems it is necessary that they be charged by voltage regulator circuits properly compensated for changes in operating temperature. The number of cells in series is obtained by dividing the maximum system charge voltage by the maximum charge voltage in volts per cell specified by the cell manufacturer.