Difference Between PWM And MPPT Solar Regulator

There are many articles on the Internet that introduce the difference between PWM and MPPT solar regulator, but most of them only let readers know the general idea: MPPT solar regulator is more efficient than PWM solar regulator. Today, Xindun Power will try to explain the difference between the two in a more easy to understand way:

1.In terms of basic principle, PWM solar regulator is equal to a DC charging switch, and it has three charging stages like MPPT solar regulator : constant current, constant voltage, and floating charge to charge the battery. Unlike MPPT solar regulator, PWM solar regulator is fully open in the early stage of battery charging, which is equivalent to the solar panel directly connected to the battery for charging. The floating charge function is not turned on until the battery power reaches 80-85%. We will explain what the floating charge function later. Now we will focus on the difference between PWM and MPPT solar regulator. MPPT solar regulator from the beginning of charging the battery, the voltage and current of the solar panel are accurately tracked through algorithms, so that the charging power is always in the most appropriate range. PWM solar regulator is like a faucet without valve. No matter how big the water tank is, it will only fill the water tank according to its own water output. In the process, some water may overflow from the water tank due to excessive water output. MPPT solar regulator is like a faucet with a valve. It adjusts the water output at all times to ensure that 99% of the water can be filled into the water tank to avoid overflow and waste.

2.In practical applications, PWM solar regulator is suitable for use with solar panels with a power of 200W or less, and MPPT solar regulator is suitable for use with solar panels with a power of 300W or even more than. Let's use a faucet as an analogy: solar panels below 200W, because the solar current and voltage generated are not large, just like the water output of the faucet itself is not large, so it is better to fill the water tank directly. If a valve (MPPT) is added, it will affect the water flow with a small water output. However, once the water output increases, if it is not controlled like PWM solar regulator, the water is easy to overflow and cause waste. Adding a valve (MPPT) makes the water output relatively stable, greatly reducing the waste of water overflow.

3. Actual data: A-level solar panels have an efficiency of 80%. For example, a 100W solar panel can generate 80W of energy in one hour under sufficient sunlight. PWM solar regulator can only allow about 75%-80% of the 80W to charge the battery, which means that only 60-64W of energy from a 100W solar panel reaches the battery per hour. MPPT solar regulator can achieve an efficiency of 99%, so almost all of the 80W capacity reaches the battery.

Xindun as a PWM and MPPT solar regulator manufacturer. There are Solar Regulator for Sale as follow: