How Does A Solar Charge Controller Work


Solar charge controllers are essential for efficient and safe charging of batteries. Solar panels that are connected directly to the battery may continue to charge until internal damage occurs.

It is not very useful to understand the electronics inside the controller, but it is important to understand how and why they are electrically connected and to have some understanding of the different types.

A solar charge controller works by regulating the voltage and current from the solar panel to the battery. It detects and monitors the battery voltage and reduces the current when the battery is fully charged. The controller maintains a floating charge so that the battery is always available.

How To Connect A Solar Charge Controller to a Battery

Most batteries for auto and marine activity have a terminal voltage of around 12 volts. The two general gatherings of batteries in common manner utilization are lead-corrosive in different structures and lithium based. Diverse kind of batteries need distinctive charging attributes – a greater amount of this later.

Whichever kind of battery you have, the essential associations are something similar. The solar panels interface with positive and adverse terminals of the regulator, the result associates with the battery terminals and a heap might possibly be associated in corresponding with the battery also (see above.)

Some solar charge controllers likewise have extra USB yields and maybe a different arrangement of terminals for a DC yield load. Nonetheless, this is ordinarily little limit, for a light, for instance.

How To Charge Different Battery Types

Many people still don't know how to charge the different kinds of batteries. Not such countless years prior, the main sort of battery for most applications were weighty lead-corrosive sort with terminals drenched in fluid corrosive.

In the time of electric vehicles there have been immense changes in energy-putting away innovation – capacity limit thickness is currently key.

The four sorts of battery displayed most importantly have specific charging qualities:

Battery Type

Full Charge Open Circuit Volts

Lead-acid (deep cycle)


Lead-acid (auto)


LiFeP04 (lithium phosphate)


Li-ion – 4 string (lithium polymer)


How Does A MPPT Solar Charge Controller Work?

The Maximum Power Point of a sunlight based charger is the voltage at which they can create the greatest charging capacity to the batteries.

The regulator contrasts the battery voltage and the sun powered charger and converts the board voltage into the worth which amplifies the current into the battery.

Thusly, the rising voltage restricts the charge current to it's most proficient worth at some random time.

How does PWM Solar Charge Controller Work?

PWM represents Pulse Width Modulation, which is essentially a depiction of its activity.

Direct current from the sun powered chargers is cleaved up into beats at a specific voltage. The charger distinguishes the voltage of the battery associated with it and computes the right charging voltage to apply, which decides the charging current.

The spaces between the voltage beats are changed electronically. The normal voltage relies upon the time between the beats.