Determining the functionality of a solar charge controller is essential for the overall health of a solar PV system. The primary indication of a malfunctioning charge controller is its inability to protect the solar battery from overcharging or discharging. To diagnose a faulty controller:
- Use a multimeter to test the components of the solar PV system.
- Measure the voltage and current of the solar panel. If readings are zero or low during sunlight, the panel may be at fault.
- Test the solar battery’s voltage. If it’s 20% less than the nominal charge, additional chargers might be needed.
- Measure the charge controller’s terminal voltage. If out of range, the controller is likely faulty and requires replacement.
It’s also crucial to note that a malfunctioning charge controller can lead to significant costs, especially if it necessitates the replacement of a solar battery. Furthermore, while charge controllers are generally durable, their lifespan can range between 10 to 25 years, contingent on the brand.
How do I know if my charge controller is bad?
Apart from protecting your solar battery from overcharging and discharging, a charge controller has many other benefits to your solar PV system. If your charge controller stops working without your knowledge, you might end up incurring a lot of cost replacing your solar battery.
For the above reason, it would be better if you checked the condition of the charge controller regularly. If you notice your charge controller is not working as expected, fix the issue ASAP! But how do you know if your charge controller is bad?
Use a multimeter to test all the components
If your solar PV system is not working, it is hard to know which component is faulty. To determine which of the components is not working, detach the charge controller and battery from the solar panel.
Measure the voltage and the current of the solar panel. If they record zero or low voltage and current when there is sunlight, then the solar panel is at fault and should be fixed.
Sometimes the battery is defective or the chargers are not enough. Use the multimeter to measure the voltage of the solar battery . If the voltage is 20% less than the nominal charge, then you should add chargers.
Use the multimeter to measure the voltage of the charge controller. The charge controller terminal voltage should bring range. Otherwise the charge controller is faulty and should be replaced.
How to know if my solar charge controller is not charging the battery?
A charge controller not working can cause a lot of issues like not charging a solar battery. There are a few ways you can tell if your charge controller is not working.
1. Check the voltage of the solar battery
If the solar panel is in the right condition and there is plenty of sunlight, then your solar battery should be displaying some voltage. Suppose the battery voltage is not changing even after hours of charging, then the charge controller is faulty.
2. Check the weather conditions
When the weather conditions do not facilitate the charging of solar batteries, then the charge controller will not pass any current to the battery. This is one way of determining why your charge controller is not working.
3. Check the wiring
If there is an open circuit between the solar panels and the charge controller, then the charge controller will not charge the battery. Ensure all the wirings are done right.
Another way of telling if your charge controller is charging or not charging your solar batteries is estimating the time taken to fully charge your solar battery. You can also observe for any error message in your charge controller.
What to do if my solar charge controller not turning on?
Your solar charge controller might not be turning on because of the following reasons;
- There is a loose or wrong wiring between the charge controller and the solar panel
- The solar panel is dirty or faulty
- The charge controller itself has an issue
- There is no enough sunlight to charge the solar battery
- And the solar battery is faulty
Each of the listed cases will result into the charge controller not displaying if any voltage or not working entirely. We will take each situation and give viable solutions.
- If there is a loose or faulty wire between the solar panel and a charge controller, use this steps to fix the issue. You can also use a user manual provided by the manufacturer to fix the wiring issue.
- Sometimes the solar panel might gather some dust after a long while. Check the condition of your solar panel regularly and clean it at least twice every year.
- A charge controller like any other device is prone to going bad. Use a multimeter to check the terminal voltage of the charge controller. If the voltage is low or zero, then your charge controller is defective and call for replacement ASAP.
- When there is not enough sunlight energy, then your charge controller and solar battery will not display any voltage. In such a case, you can wait until the sun is back to test if the controller is viable. Alternatively, you can use other methods of charging your solar battery.
- A defective be solar battery cannot show and voltage or charge a charge controller. In such a case, you can replace your solar battery with a battery with the same capacity.
If the manufacturer provides a warranty, you can advantage of the warranty.
Overall, a controller not working is like a chronic disease to your solar PV system.
How long does a charge controller last?
The longevity of the charge controller depends on the brand of the charge controller. However, standard charge controller last between 10-25 years.
Your charge controller will also last longer if you take good care of your solar PV system.
How to reset the solar controller?
If your charge controller is not working you can either perform a hard or a soft reset. Resetting a solar charge controller means you are returning your charge controller to factory settings mode. This means all the errors will be fixed by the time your charge controller is reset.
Soft reset
Hold all the four buttons on the face of the controller for 15 seconds. If the charge controller is not fixed try a hard reset.
Hard reset
- Detach all the wire cables from behind the charge controller.
- Let it stay for about 20 minutes before attach it back to the grid.
- Reconnect the positive and the negative of the battery first.
- Then reconnect the solar panel positive and negative. The charge controller will have gone back to factory settings.
Resetting your charge controller should be done at night to ensure efficiency and safety. Otherwise, if you are resetting during the day, cover your solar panel with a black vinyl paper.
How do I know if my solar battery is bad?
Determining if your solar battery is bad or failing involves a combination of physical inspection, performance monitoring, and testing. Here are some steps you can take to assess the health of your solar battery:
Visual Inspection:
Swelling or Bulging: Batteries that are swollen or bulging may be overcharged or have experienced a failure.
Corrosion: Check for any signs of corrosion around the terminals. Corrosion can indicate that the battery is releasing acid or gas.
Leakage: Any signs of liquid leakage from the battery are a clear indication of damage.
Check Voltage Levels:
Using a multimeter, measure the voltage across the battery terminals. A fully charged 12V battery, for example, should read around 12.6V or higher. If it’s significantly lower, the battery might be discharged or bad.
Capacity Test:
Fully charge the battery and then discharge it using a known load, like a light bulb. Monitor how long the battery can power the load compared to its rated capacity. If the battery discharges much faster than expected, its capacity may be diminished.
Monitor Performance:
If your solar system has a monitoring system, check the battery’s state of charge (SOC) and depth of discharge (DOD). A battery that doesn’t hold its charge or discharges too quickly may be nearing the end of its life.
Check Battery Age:
Batteries have a limited lifespan, typically ranging from 5 to 15 years depending on the type (lead-acid, lithium-ion, etc.) and usage. If your battery is approaching or has exceeded its expected lifespan, it might be time for a replacement.
Listen for Sounds:
Some batteries, especially older models, might make a hissing sound when they’re failing.
Hydrometer Test (for Flooded Lead-Acid Batteries):
This test measures the specific gravity of the electrolyte in each cell. A low specific gravity in one or more cells indicates a bad or weak cell.
Load Test:
This involves applying a load (resistor) to the battery and measuring the voltage drop. If the voltage drops too quickly, the battery might be bad.
Check for Consistent Temperature:
Batteries that are failing might have inconsistent temperatures across their cells. If one part of the battery is hot while another part is cold, there might be an issue.
Professional Testing:
If you’re unsure about the health of your battery, consider having it tested by a professional. They have specialized equipment that can provide a detailed assessment of the battery’s health.
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”.
