The Lead Acid Battery

This is the type of battery you are most likely to be using in a static situation. It is the most cost effective,and is capable of producing high currents.
These have been around for a long time, having been invented in the mid 1800's with the basic design principally unchanged.

The battery consists of individual cells, each producing approximately 2 volts. Each cell consists essentially of two electrodes of lead, in a 33% solution of sulphuric acid. As the battery is charged however, chemical changes occur in both the electrodes and the electrolyte (the sulphuric acid).

The lead acid battery described above is known as a wet cell lead acid battery due to the electrolyte being liquid.

Two other types are also available, both of which may be termed a sealed lead acid battery though they do have a pressure relief valve:

• Absorbed Glass Mat (AGM) - where the electrolyte is absorbed in a fine fibreglass mat between the electrodes
• Gel - where the electrolyte is in the form of a gel.

Both the above types of battery can withstand being turned over without spilling electrolyte and therefore have specific uses.

Due to these batteries being at least semi sealed, care has to be taken to ensure that no excessive gassing occurs (which occurs at higher charging voltages). Therefore these batteries may require a specific charge controller. Charging with the wrong type of controller can cause an explosion.