Technical progress with battery design and the availability of new materials have enabled the realization of completely maintenance-free lead–acid battery systems [1,3]. Water losses by electrode gassing and by corrosion can be suppressed to very low rates.
The active masses of the negative and positive electrodes were electrochemically prepared on lead plates, a process still used even today. Lead–acid batteries are comprised of a lead-dioxide cathode, a sponge metallic lead anode, and a sulfuric acid solution electrolyte.
A lead-acid battery is a series of plates connected to top lead connected to posts. If the top lead, posts and intercell connectors are not sufficiently large enough to safely carry the electrons, then overheating may occur (i2R heating) and damage the battery or in the worst cases, damage installed electronics due to smoke or fire.
One of the most important properties of lead–acid batteries is the capacity or the amount of energy stored in a battery (Ah). This is an important property for batteries used in stationary applications, for example, in photovoltaic systems as well as for automotive applications as the main power supply.
Another important performance factor for lead–acid batteries is self-discharge, a gradual reduction in the state of charge of a battery during storage or standby. The self-discharge takes place because of the tendency of battery reactions to proceed toward the discharged state, in the direction of exothermic change or toward the equilibrium.
However, lead–acid batteries have inferior performance compared to other secondary battery systems based on specific energy (only up to 30 Wh/kg), cycle life, and temperature performance. The low-energy density limits the use of lead–acid batteries to stationary and wheeled (SLI) applications.