A solar regulator (also known as a charge controller) is used in conjunction with a stand alone (off grid) system, or a grid connect solar power system that incorporates a backup battery bank. For a grid connect solar power system that doesn’t use batteries, a solar regulator is not needed.
A solar regulator is a small box consisting of solid state circuitry that is placed between a solar panel and a battery. Its function is to regulate the amount of charge coming from the panel that flows into the deep cycle battery bank in order to avoid the batteries being overcharged. A regulator can also provide a direct connection to appliances, while continuing to recharge the battery; i.e. you can run appliances directly from it, bypassing the battery bank; but the batteries will continue to be charged.
Modern solar regulators are very efficient and will outperform just about any 3 stage mains power battery charger.
Selecting a solar regulator
To determine the size regulator you’ll require, check the amp ratings of your solar panels and add those figures up and that will give you the minimum size charge controller you’ll need – or you can use our system builder tool which will tell you the size you’ll need based on various selections.
When selecting a solar regulator, it’s important to also look ahead – if you think you’ll be adding to your system, it pays to buy a regulator rated as high as possible, which can save you money when you add additional solar panels.
Low voltage disconnect
Some charge controllers include a Low Voltage Disconnect (LVD) feature. This monitors the battery level and will disconnect any load connected to the battery if the voltage drops to a point where continued draw can cause permanent battery damage. This feature is a great protection for your deep cycle battery investment as a battery that has been discharged too deeply will have a far shorter serviceable life.
Solar regulator maintenance
A solar regulator requires no maintenance aside from regular checks of the wired in connections to see that they are tight and corrosion free. A solar regulator should be mounted out of direct sunlight and in an area where there is decent air flow. While the solar regulators of today are extremely robust; performance and serviceable life will suffer in extreme heat.
As an additional safety mechanism to protect the charge controller, your batteries and appliances, plus reduce fire risk, it’s wise to place an appropriately rated fuse between the solar panel and the regulator.