Solar Charge Controllers

Solar panels cannot be connected directly to a battery bank. Solar charge controllers transform the voltage coming from one or multiple solar panel(s) and transform them into a voltage that the battery bank needs to charge.

Charge controllers have to be programmed for the type of battery they are connected to: flooded, AGM, lithium

solar charge controllers have at least two pairs of cable terminals: battery (+/-) and solar PV (+/-). Some smaller charge controllers often have another pair for load output (+/-). These are very limited in their power output, but they often can be programed to work as a battery protection, or even a timer for lights.

The main properties of a solar charge controllers are

• maximum solar voltage (needs to be higher than the combined open-circuit voltage (Voc) of your solar panel array)
• maximum charging current (needs to be high enough to charge your panels solar power into the batteries: divide solar power by the battery voltage)

See the video further below for more details.

There are two types of solar charge controllers:

(Pulse Width Modulation)

These charge controllers are low in price, but less efficient than MPPT charge controllers. Recommended only for very small solar PV systems.

(Maximum Power Point Tracking)

These charge controllers are more expensive, but the increased efficiency and other advantages make up the price, because less solar panels are needed for the same energy yield.

The basics:

Here a more detailed video: