FAST CHARGERS

Fast discharge of lead-acid batteries

Lead–acid batteries designed for starting automotive engines are not designed for deep discharge. They have a large number of thin plates designed for maximum surface area, and therefore maximum current output, which can easily be damaged by deep discharge. Repeated deep discharges will result in capacity loss and ultimately in premature failure, as the disintegrate. When a lead acid battery discharges too quickly, it can lead to sulfation, where lead sulfate crystals form on the battery plates. This process reduces capacity and shortens lifespan. [pdf]

FAQS about Fast discharge of lead-acid batteries

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.

How long does a deep-cycle lead acid battery last?

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.

What is fast charging of a lead–acid battery?

Thus, fast charging of a lead–acid cell can be achieved without a loss of cycle-life, despite the fact that higher currents are forced into the cell. 1. Introduction The fast charging of a lead–acid battery, or indeed other secondary rechargeable batteries, is a key technology for electric vehicles.

How does a lead acid battery work?

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.

How fast can a lead-acid battery charge?

Experiments on a 12 V 50 Ah Valve Regulated Lead Acid (VRLA) battery indicated the possibility of 100 % charge in about 6 h, however, with high gas evolution. As a result, the feasibility of multi-step constant current charging with rest time was established as a method for fast charging in lead-acid batteries.

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.