How to size a solar charge controller?

May 20, 2024

Generally speaking, solar charge controllers are divided into MPPT solar charge controller and PWM solar charge controller. The size of solar charge controller mainly depends on two factors: the current flowing from the solar cell and the voltage connected to the system. Sizing a solar charge controller requires the following steps:


Step 1: Determine solar cell specifications First, you need to determine the wattage, voltage, and current of each solar panel.


Step 2: Match battery voltage Make sure the charge controller voltage matches the battery. If they do not match, it is easy to damage the battery and pose a safety hazard.


Step 3: Calculate maximum current output Calculate the maximum current output in parallel: With a parallel connection, the voltage remains constant as the current accumulates, adding current from each panel. When solar panels are connected in series, the current remains the same but the voltage increases. So if you have solar panels in series, you need to add voltage.


Step 4: Add security scope The safety margin is added to account for increased current due to strong sunlight conditions or other circumstances. A common practice is to add 25%.


Step 5: Consider future expansion We often choose a larger charger than the system we are currently using. This avoids the need to replace a larger charger when the system is expanded, adding a lot of convenience for future expansion.

Need Help? Chat with us

leave a message
For any request of information or technical support, fill in the form. All fields marked with an asterisk* are required.
Looking for FAQs?
Contact us #
+86 -13244735151

Our hours

Mon 11/21 - Wed 11/23: 9 AM - 8 PM
Thu 11/24: closed - Happy Thanksgiving!
Fri 11/25: 8 AM - 10 PM
Sat 11/26 - Sun 11/27: 10 AM - 9 PM
(all hours are Eastern Time)




Contact Us