Solar Panel Voltage Regulator: Its Types & Benefits in 2023

Earth receives a huge amount of energy directly from the sun in the form of heat. We use solar panels to collect sunlight and convert it into electricity. In our previous posts, we have discussed how solar panels convert sunlight into electricity

But, do you know the excessive sunlight can cause unnecessary heating and harm to the batteries and also to the electronics associated with it.

However, the sun is never in a stable position. So, the voltage received from the sun is never constant due to the fluctuating intensity of the sunlight.

In this post, I will describe the use of a solar panel voltage regulator and why you need to install it, and also the benefits of it.

So, without furthermore discussion, let’s begin:

What is a Solar panel voltage regulator?

Batteries are used to store the power generated from solar panels.

A solar voltage regulator is a device used to prevent batteries from overcharging.

Also, it regulates or controls the voltage coming from the solar panel to the batteries and electronics associated. 

Solar panel voltage controllers are essential in off-grid solar systems.


Types of Solar panel voltage regulator

There are two main types of voltage regulators:

  1. PWM: Pulse Width Modulation 
  2. MPPT: Maximum Power Point Tracking

PWM: Pulse Width Modulation

  • These regulators contain a direct connection between the solar panels and battery storage.
  • The voltage controllers use a transistor instead of a relay to open the array. 
  • The PWM regulator self-adjusts by varying the widths and speed of the pulses sent to the battery.
  • PWM voltage regulators cost less and are used in small solar panel systems.

MPPT: Maximum Power Point Tracking

  • These voltage controllers allow the array voltage to vary from the battery voltage which makes it easy for the regulator to find a point on which the solar array produces the maximum power.
  • In the case of larger solar arrays, heat dissipation can become a problem.
  • MPPT controllers are typically step-down converters, so the array voltage always needs to be higher than the battery voltage. 
  • The main purpose of the MPPT solar regulators is not only to prevent the solar power system from losing power generated by solar panels but also to get the maximum power from the solar array.
  • MPPT controllers are more expensive than the PWM ones but these are also more efficient in terms of adding additional losses to the system.

Circuit Diagram

Below is a circuit diagram of solar panel voltage regulator from homemade-circuit projects:

Solar voltage regulator circuit
Circuit Diagram of Solar Panel Voltage Regulator

NOTE: R4 can be removed, as it has no real importance. You can replace it with a wire link.

Also, Trackside PCB Design (R4, Diode, and S1 not included…R4 is not important and may be replaced with a jumper wire).

Why do you need it?

Since the voltage received from solar panels is never stable and varies according to the position and intensity of the sunlight.

This voltage is fed to the batteries for charging then it can cause harm and lead to unnecessary heating of the battery and associated electronics.

So, to regulate the voltage from the solar panel, a voltage regulator is used in between solar panel output and the battery input.

Working of Solar panel voltage regulator

The solar panel voltage regulator acts as a blocking diode when the battery voltage is greater than the solar array voltage. 

The voltage regulator ensures that the voltage from the solar panel never exceeds the safe value required by the battery for charging.

Generally, there is no need for a charge controller with small maintenance. If the panel puts out less than or equal to 2 watts for each 50 battery amp-hours, then there is no need for a regulator.


The solar panel voltage regulators can be installed outdoors.

It is best to choose a mounting position that is protected from direct falling of rain and sunlight.

This can be accomplished by mounting the voltage regulator on the backside of the solar panel.

Benefits of Solar Panel Voltage Regulator

  • Solar panel voltage regulators can be used with any size of Lead-Acid batteries.
  • This will be no reverse current flow.
  • It provides safe flow charging for long battery life.
  • It prevents unnecessary heating from the electronics and batteries associated.
  • The voltage regulator disconnects the loads plugged in case of a low battery state of charge and reconnects the loads when the battery is charged again.


There are various storage options for solar power. Among all Lead-Acid battery storage is most used in off-grid solar powered systems.

Solar voltage regulators are essential components of off-grid solar systems. 

Without them, batteries will be unable to keep up with the current fluctuations received from the solar array.

Furthermore, while selecting a solar voltage regulator, you must first ensure that the regulator is compatible with your system’s voltage and select a product that can handle the maximum output current of your solar panel or array.

Hope you find this post helpful!

If you have any queries, you can ask in the comment section below this post.

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  1. The environment is full of pollutants and we may wake up one day, that the earth we once live is no longer the same. Solar energy is the best alternative when it comes to environmental protection.

  2. When the lockdown started we considered installing solar panels as a source of electricity for the house. Electric consumption and bill went 50% more of what we normally consume as every appliances is on most of the time.

  3. I always liked the idea of using solar energy However I had no idea that we can actually regulate the consumption of solar energy via solar panels. It is fascinating to know that it can cause damage and that it can be regulated. Wonderful.

  4. After reading this I’ve come to the conclusion that I need a Solar panel voltage regulator asap. I just got word that my mac battery is needing a new one and I wish I could get this in place? I’m not too sure but i have a lot of my devices overheating…