In solar power terms, solar panels batteries definition is an electrical accumulator to store the electrical energy generated by a photovoltaic panel in a solar energy installation. Sometimes they are also known as photovoltaic batteries.

When we install solar panels in an autonomous facility, a battery system is mandatory to ensure we will have power when we need it. Moreover, in case our home is connected to the electrical grid, home batteries are helpful in case of a power outage.

Solar battery technology stores the electrical energy generated when solar panels receive excess solar energy in the hours of the most remarkable solar radiation.

Not all photovoltaic installations have batteries. Sometimes, it is preferable to supply all the electrical energy generated by the solar panels to the electrical network. Extensive electrical facilities that use renewable energy are connected to the electrical grid.

The batteries have the function of supplying electrical energy to the system at the moment when the photovoltaic panels do not generate the necessary electricity.

When the solar panels batteries can generate more electricity than the electrical system demands, all the energy demanded is supplied by the panels, and the excess is used to charge the batteries.

Batteries transform the electrical energy they receive from photovoltaic modules into chemical energy. This conversion is carried out from the reaction that occurs when two different materials, such as those of the positive and negative plates, are immersed in the electrolyte. The electrolyte is a solution of sulfuric acid and water.

Electricity flows from the battery as soon as an electrical circuit is connected between the positive and negative poles.

As the battery discharges, the lead composition in the plates is more similar. At this time, the density of the acid decreases, and the voltage between terminals decreases.

The ability to undergo a constant charging and discharging process is known as the cycling resistance of a battery.

Solar batteries work using DC electricity. Since the PV panels generate a direct current, there is no problem when charging. However, most domestic devices at home work using AC. Usually, the system has an inverter that converts DC into AC.

The useful life of a battery for solar installations is usually around ten years.

However, their useful life plummets if frequent deep discharges ( 50%) are made. Therefore, it is advisable to install enough capacity so that 50% of the discharge is not exceeded.

Another crucial factor is temperature. The useful life will be around ten years if the temperature is kept between 20 and 25ºC. On the other hand, if the temperature is altered by 10ºC, the useful life can be reduced by up to half.