Solar and Wind Power and Alternative Energy Information

Charge Controllers

A charge controller is needed, when considering an alternative energy source that will store electricity in batteries, and sits between the electric power source and the deep cycle battery.

A charge controller prevents the electric power source, wind power, solar power or hydro-electric power from over charging the deep-cycle batteries.

Charge controllers also ensure that the batteries are charged at the maximum rate and that the batteries are not over-charged when almost fully charge i.e. from a large power surge through the alternative energy system.

Generally, two types of charge controller are available; pulse width modulated or "shunt type".

Pulse Width Modulated or PWM charge-controllers work by switching on and off the power supplied to the batteries, very quickly. The amount of on / off time varies and this controls the power delivered to the batteries.

Shunt type charge controllers simply shunt excess power to a dump load - for instance a hot water heater. This can be useful in that no energy is wasted but may be impractical for some alternative energy power systems.

Charge Controllers limit the amount of charge to the batteries to ensure safe charging. A key feature of a charge controller is the ability to prevent excessive charge being delivered to the batteries, and knowing when to stop delivering charge to the battery to avoid damage.

Charge controllers ensure that the batteries are charged at the maximum rate that they safely can stand when the power is available. Because power can be delivered faster than the chemical ability of the battery to cope - it is important to have a reliable charge controller that is able to accurately sense charge delivered to the battery.

Charge controllers also ensure that the deep-cycle batteries are not overcharged when nearing full charge and are not overheated when they are discharged.

Charge Controllers

Charge Controllers on the web