A car’s battery is designed to provide a very large amount of current for a short period of time – known as micro-cycling (except for stop/start vehicles). This surge of current is needed to turn the engine over during starting. Once the engine starts, the alternator provides all the power that the car needs. Used in this way a car battery can last a number of years. To provide a large amount of starting current, a car battery uses thin plates in order to increase the plate surface area.
A leisure battery is designed to provide a steady amount of current over a long period of time. It can provide a surge when needed but less than a car battery can. Leisure batteries are also designed to be discharged over and over again (something that would ruin a car battery very quickly). To accomplish this, leisure batteries sometimes use thicker plates and glass mat separators are added to increase the life of the positive plates.
The purpose of a leisure battery is to provide power for trolling motors, uninterrupted power supplies (UPS) and other accessories for marine, recreational vehicle (RV), commercial and stationary applications.