Solar Charge Controller

Solar Charge ControllerWhat is a solar charge controller?

The solar charge controller manages the power entering the battery pack from the solar cell array. It ensures that the deep cycle battery will not be overcharged during the day, and the power will not flow back to the solar panel overnight and drain the battery. Some charge controllers have additional functions, such as lighting and load control, but managing power is their main job.

There are two different technologies for solar charge controllers, PWM and MPPT. Their performance in the system is completely different from each other. MPPT charge controllers are more expensive than PWM charge controllers, and it is usually worth paying more.

How to choose a solar charge controller?

A solar charging controller (or sometimes called a regulator) is an important part of every solar charging kit. The main function of the controller is to protect and automate battery charging. It does this in multiple ways:

1. Monitor battery voltage

The controller detects when the battery voltage is too low. When the battery voltage is lower than a certain level, the controller will disconnect the load from the battery to prevent the battery from draining.
A fully exhausted battery will lose part of its total capacity.
If a load is connected, the low voltage will still damage the battery.

2. Lower the voltage of solar panels

If there is no controller between the solar panel and the battery, the battery panel will generate too much voltage for the battery to process, which will overcharge the battery and seriously damage the battery. Overcharging of the battery may cause the battery to explode!

3. Stop reverse current at night

The controller will prevent any current from flowing back to the solar panels at night. This prevents any damage to your solar charging kit.

There are many different types of controllers on the market. Choosing the right controller depends on the solar system you want to generate.


An excellent small device with compatibility, simplicity, and practical understanding of solar panels, batteries and loads: it is included in most of our small and medium kits.

Because it uses PWM technology, the current and voltage loss between the panel and the battery is almost zero. It can extend battery life and prevent overcharge, undercharge, short circuit and overheating.

The charge controller does not need to be used separately for a panel and a battery; a 10A PWM controller is used to regulate the charging of the parallel solar panel array, with a total power of 160W. If you have a 20A PWM controller, you will be able to adjust the solar panel group, 12V battery up to 320W, 24V battery up to 640W. The PWM controller can also be used to connect the solar panel to the 12V battery of the battery pack, provided that the batteries are the same size and in good condition. The 10A controller is also very compact, measuring only 14 x 7 cm.

MPPT solar charge controller

MPPT solar charge controller stands for “Maximum Power Point Tracking”. It will measure the Vmp voltage of the panel and down-convert the PV voltage to the battery voltage. Because the power entering the charge controller is equal to the power output from the charge controller, when the voltage drops to match the battery pack, the current will rise, so you will use more available power from the panel. You can use solar panels with a higher voltage than batteries, such as the more easily available 60-cell nominal 20V grid-connected solar panels. Using 20V solar panels, you can charge a 12V battery pack, or two in series can charge a 24V battery pack, and three in series can charge a 48V battery pack. This opened up a wide range of solar panels, which can now be used in your off-grid solar system.

Dual battery controller

This can be used to monitor and regulate two independent (electrically isolated) batteries at the same time.

It is an indispensable item for people who want to charge leisure batteries and engine batteries at the same time, or who want to charge a set of 12V leisure batteries and starter batteries at the same time.

The user has two charging options: charge two connected batteries at an equal rate, or give priority to charging one battery (for example, 80% of the power is used for the engine battery and 20% of the power is used for the leisure battery). The controller can be equipped with a remote display so that the user can better control the adjustment between the two batteries. Although called a “dual battery controller”, it can also be used to charge a battery-a second battery can be added later.

Waterproof controller

These controllers are designed for humid environments. In terms of functionality, they are almost identical to standard 10A PWM controllers. It has multiple settings for timers to control the work of the load, which is very suitable for street lighting and also very suitable for anyone who wants to set up a solar charging kit on board.

Controller with LCD display

The programmable function allows the user to customize the charging process by setting the battery type and capacity, selecting the charging voltage for each stage, setting the protection parameters, and switching the load through the timer.

These controllers put the power in the hands of the owner and make the solar circuit more advanced and controllable. The LCD display can provide you with a lot of information, including:

-Solar panel current/voltage, battery current/voltage
-The charge status of the battery
-Current charging stage