PWM vs MPPT Charge Controllers

PWM vs MPPT Charge Controllers…What are the differences between these two terms in the solar energy industry? Let’s find out!

The Most Common PWM vs MPPT Charge Controllers

First off, what is a Charge Controller?

The purpose of a Charge Controller is to control how much power goes into the battery. A Charge Controller is the middle part of a solar energy system. It takes the power generated from Solar Panels to the solar storage batteries in a way that does not overfill or empty out your solar storage batteries.

Solar panels by themselves do not know how much to charge and as a result charge the battery non-stop. If you connect your solar panels to your battery without a charge controller in between, your batteries will become overcharged and eventually blow up. 💥

What is a PWM Charge Controller?

The “PWM” is the acronym of Pulse Width Modulation. Pulse Width Modulation is an old-school proven technology for solar energy systems. It will collect the power out of your solar panels and pass it to the solar storage batteries.

Straightforward PWM, or pulse width modulation solar charge controllers have an immediate association from the solar panels to the battery and utilize a fundamental fast switch to balance or control the battery charging. The switch (transistor) is open until the battery arrives at the ingestion charge voltage. At that point, the switch begins to open and close quickly (several times for every second) to reduce the current and keep a steady battery voltage.

This works alright, however, the issue is the solar panel voltage is pulled down to coordinate the battery voltage. This then pulls the panel voltage away from its optimum operating voltage (Vmp) and decreases effectiveness.

PWM solar charge controllers are an incredibly easy alternative for little systems where a solitary solar board is utilized for straightforward applications like solar lighting, outdoors, and fundamental things like USB/telephone chargers.

What is an MPPT Charge Controller?

The “MPPT” is the acronym of Maximum Power Point Tracking. MPPT controllers are further developed than PWM controllers and empower the solar panel to work at its optimum voltage for maximum power output. Utilizing this innovation, MPPT solar energy controllers can be 30% more proficient, contingent upon the battery voltage and sort of solar panel connected.

As you might be familiar, there are charging stages for different purposes (Check: 3 – Stage Battery Charging). MPPT Charge Controllers are a multi-stage charge controller and correspond with most of the solar systems.

PWM vs MPPT Charge Controllers

We got the idea of what is an MPPT Charge Controller & what is a PWM Charge Controller. Let’s talk about the advantages, differences, and uses of both charge controllers and give a couple of examples.

The Most Common PWM & MPPT Charge Controller Differences

The most common differences are the price, efficiency, size, and stages of these two kinds of charge controllers. An MPPT Charge Controller will provide more power without using a large field of solar panels but will cost more. Simultaneously, a PWM Charge Controller can be more affordable but uses a larger area and more solar panels.

Check out The Most Common MPPT & PWM Charge Controller comparison table below:

Multi – StageCharging States3 Stage
30A – 100ASize20A – 60A
LessRequired Solar PanelsMore

Which Charge Controller Is Best for Your Solar System Needs?

As a solar energy installer, you might already know how important it is to choose the right charge controller for your off-grid solar energy system (Visit: What Is an Off-Grid Solar System?). But which charge controller is the best for your solar energy system?

Of course, it all depends on how big the project is!

If you are installing a smaller project, why spend more money on MPPT Charge Controllers when you can efficiently run the system with an affordable PWM charge controller?

PWM Charge Controllers would easily accomplish the job for smaller projects such as cabins, tiny homes, RVs, etc. Let’s take a moment to consider a cabin.

Before installing a solar system to a cabin, you need to know how much energy the cabin consumes and how the climate is in that location. Assume you are guaranteed that the cabin will just utilize a specific amount of energy, and it will consistently require a similar amount of energy with no expansion. All things considered, you can install a system that is intended to work with PWM Charge Controller, and it will cost less while still achieving the job!

If you are installing a larger project, why generate less power with a PWM Charge Controller when you can undoubtedly collect more power with a cost-effective MPPT Charge Controller?

MPPT Charge Controllers would be the best option for larger projects such as townhouses, two-story houses, corner-stores, etc. Let’s think of a corner-store.

Regarding larger projects such as a corner-store, you want to ensure that the corner-store always produces enough energy for its electric-powered gear. In this scenario, your most ideal alternative is to choose MPPT Charge Controllers to collect more power out of your solar panels and keep the battery charged whatever amount as could reasonably be expected.

Long story short:

If you have a larger area that you can install many solar panels and collect enough power, then PWM Charge Controller would be the best option.


If you have a limited area where you cannot install too many solar panels and you’re using more power than your panels can produce, then MPPT would be the best option for you.

The Most Common PWM Charge Controllers

Check out the most common PWM Charge Controllers that are being used on the solar systems between 2020 – 2021

The Most Common MPPT Charge Controllers

Check out the most common MPPT Charge Controllers that are being used on the solar systems between 2020 – 2021