A solar charge controller might stop working efficiently due to a solar battery issue, a solar charge controller, a solar battery issue, and the whole setup. There are no other ways of telling if your charge controller is not working unless you do some test. Is the process of testing and diagnosing issues with a charge controller hard?
You can test if the charge controller is working by using a multimeter. If any current flow from the solar panel, the multimeter will detect any voltage reaching the charge controller. Other ways you can use to check if your charge controller is working will be discussed below.
How do I know if my charge controller is working?
A charge controller aims to control the amount of power getting into your solar batteries. It ensures that the solar battery charges even when the weather condition is not conducive for charging and prevents the solar battery from overcharging when the sun is hot. If you are using solar battery charge controllers, it is not very hard to tell if it is not working.
On the face of the solar battery charge controller is a screen that displays the amount of voltage available in your battery. If, after some hour, the readings have not changed, it means that either the charge controller, the wiring system, the solar battery, or the solar panel is not working.
Another way of checking if your charge controller is not working is by measuring the voltage available in your battery before you start charging and after some hours. If the multimeter readings have not changed, the charge controller is not working.
Why is the solar charge controller battery blinking?
If the solar charge controller is blinking green, then it means that the solar battery is complete, and charging will be stopped—your solar charge controller blinking red means there is a fault with your controller. The issue might result from arc fault or ground fault.
You can contact your solar charge controller to find out why it keeps blinking. However, you can troubleshoot the issue and reconnect your solar charge controller if you are a tech guru.
How do you troubleshoot a charge controller?
If your solar charge Controller is not working, the chance is that the whole solar PV system is not working. You can troubleshoot the problem by following these simple steps.
1. Check the multimeter
A multimeter can detect any DC and C produced by your solar panel. Check the readings on your multimeter in intervals. If the voltage does not change over time, there must be a problem with either the solar panel, the solar battery, or the solar controller.
2. Check if the wires and fuses are installed properly
A solar charge controller cannot get any voltage from the solar battery if the wires are loose. Tighten the terminals which loosen over time, and replace any broken wires. It would be best if you also replaced any broken brown fuses and terminals.
3. Ensure the solar panel is exposed to direct sunlight
Sometimes the charge controller might not show any reading because the solar panel is blocked from reaching the sun. Place the solar panel on the sun’s path and clean all the dust and leaves particles to ensure maximum sunlight harvesting.
4. Check if the solar battery is working properly
Even with a charge controller present, a faulty solar battery will not absorb any energy from your solar battery. In most cases, the solar battery can stop working if it has finished its life expectancy or if you bought cheap solar batteries.
Use a voltmeter to check if any charge is available in your battery. If the battery is faulty, it would be best to replace it with a working solar battery.
Sometimes your solar charge controller is not working because it is low quality. The low-quality charge controller will jam when a lot of energy is being sent through it.
Arc fault and ground fault might be other reasons your charge controller cannot detect any charge. You can hire an electrician to troubleshoot the issue with your charge if you have no idea how.
Conclusion
A solar charge controller aims to improve the charging of your solar battery even on a cloudy day. It also prevents your solar battery from overcharging when the solar is hot.
If your solar charge controller is not working, you should check the following:
- Solar battery condition.
- Wiring setup.
- Positioning of the solar panel.
- The condition of the solar charge controller.
Solar charge controllers have a screen that displays the amount of voltage available in tour solar battery. It also has light indicators that show when there is an error in your solar charge controller and show when the solar charge controller is complete.
If the solar battery blinks green, it shows that the battery is complete, and charging will be stopped. A red blinking means an error either because of arc fault or ground fault.

Eng. Matthew Joseph Nandirio is the Founder of walkingsolar.
After graduating from the University of Houston in 2002, matt started working as a Solar Electrical Engineer for several multi-national solar energy companies.
He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research.
He now shares his 20 years of expertise through his articles on the walkingsolar website.
Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.