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.
After using your battery, especially if it has been deeply discharged, charge it as soon as possible. Deep discharges (below 50% state of charge) can lead to sulfation, where lead sulfate crystals form on the battery plates, reducing capacity and shortening the battery’s cycle life.
A deep-cycle lead acid battery should be able to maintain a cycle life of more than 1,000 even at DOD over 50%. Figure: Relationship between battery capacity, depth of discharge and cycle life for a shallow-cycle battery. In addition to the DOD, the charging regime also plays an important part in determining battery lifetime.
The batteries should be charged in a well-ventilated place so that gases and acid fumes are blown away. The lead-acid battery should never be left idle for a long time in discharged condition because the lead sulfate coating on both the positive and negative plates will form into hard crystals that will be difficult to break up on recharging.
Sulphuric acid is consumed and water is formed which reduces the specific gravity of electrolyte from 1.28 to 1.18. The terminal voltage of each battery cell falls to 1.8V. Chemical energy is converted into electrical energy which is delivered to load. The lead-acid battery can be recharged when it is fully discharged.
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.
OverviewTypes of lead–acid deep-cycle batteryNew technologiesApplicationsRecyclingSee alsoExternal links
A deep-cycle battery is a battery designed to be regularly deeply discharged using most of its capacity. The term is traditionally mainly used for lead–acid batteries in the same form factor as automotive batteries; and contrasted with starter or cranking automotive batteries designed to deliver only a small part of their capacity in a short, high-current burst for starting an engine.