Page 27 - PS Battery Guide May 18

Battery guide For PowerSpout

4kW PV array connected via 70 amp Fanpusun MPPT

What is electricity and what is a battery?
Electricity is the flow of electrons along a wire. Metal is a good conductor of
electricity as the electrons in each atom of metal are free to move from one atom
to another.

Consider how difficult it is to store the energy of a car that is moving.
Understanding the fact that electricity is the flow of electrons helps us to
understand that electricity is also difficult to store, as it is energy in motion.

Batteries do not store electricity as such but use the flow of electrons to alter the
number of electrons in the chemicals inside the battery. Then when the battery is
discharged the chemicals return to their original state. However, the chemical
process means that batteries degrade with use and time.

Renewable energy systems normally use batteries based on lead-acid chemistry,
as they are still the most cost effective and readily available type. Lead-acid
batteries are made from plates of lead in a solution of sulphuric acid. While the
discharging and recharging of lead acid batteries is a reversible process all lead
acid batteries lose health when not charged.

The car battery is a lead-acid battery. A car battery is designed for starting a car’s
engine and so has thin plates to provide as much surface area as possible,
allowing the chemical reaction to occur in a short time. This type of battery can

© 2018 EcoInnovation Ltd (NZ) Page 27
Last reviewed 19/6/18