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How to choose a solar controller
- Sep 07, 2018 -

The widely used solar photovoltaic power generation system consists of photovoltaic modules, solar controller (or charger), battery and load. The solar controller (or charger) is the brain of the whole solar power generation system. The command center plays an important role although it accounts for a very small proportion of the system cost. Use. Therefore, whether the whole solar photovoltaic power generation system can reflect the maximum value, choosing a good solar controller is the key link.

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Solar controller classification

The popular solar controllers on the market mainly include ordinary solar controllers, PWM solar controllers and MPPT solar controllers. Ordinary solar controller is the first generation technology. The working principle is to directly hang the output of the solar panel to the battery port. When the battery is sufficient, it will be disconnected. Because of the internal resistance of the battery, it is difficult to fill the battery, and the solar battery The board is not fully utilized, and the MPPT tracking efficiency is only 70 to 76%, which has been eliminated by the market and is rarely used. PWM solar controller is the second generation technology. Now it is the most on the market. The working mode is PWM control. Compared with the ordinary solar controller, it has improved a lot. It can solve the problem of battery charge dissatisfaction. The MPPT tracking efficiency is 75~. 80%, but solar panels are not fully utilized. The MPPT solar controller is the third-generation technology, the highest-end solar controller. MPPT solar controller refers to the solar controller with "Maximum Power Point Tracking" function, which is an upgraded product of PWM solar controller. MPPT solar controller can detect solar panel voltage and current in real time, and Continuously track the maximum power (P=U*I), so that the system always charges the battery with maximum power. The MPPT tracking efficiency is 99%, the whole system has a high power generation efficiency of 97%, and has excellent management of the battery, which is divided into MPPT. Charging, constant voltage charging and constant voltage floating charging. With advances in technology and energy savings, the trend of replacing traditional PWM solar controllers with MPPT solar controllers is irreversible.

Table 1 Comparison of several solar controllers

MPPT tracking efficiency


Charging   management technical difficulty



Market   acceptance

Ordinary solar controller                            


Not fully charged



First generation

Be eliminated

PWM solar controller






Second generation

Widely used

MPPT solar controller                   


Very good



Third Generation


 In short, the MPPT solar controller will eventually replace the traditional solar controller.