How to Check If Solar Panel is Charging Battery?

Solar panels are used for storing electrical energy in batteries and reusing it. When you own a solar panel, it’s important to verify whether it’s charging the battery correctly. Solar installation is a crucial process. In this article, we will explore how to check if a solar panel is charging a battery.

How to Check if Solar Panel is Charging Battery?

Here are a few ways to determine whether your solar panel is properly charging batteries:

1. Check the Battery

Firstly, inspect whether your battery is connected. If there is any corrosion on or inside the battery, it may prevent charging. Loose wires connecting the solar panels to the battery terminals can also cause issues.

For a thorough inspection, use a digital multimeter to check if the battery is charging; if it is, the voltage will increase. Otherwise, the multimeter will indicate a solar output voltage of 15 V or above. A battery may also stop working if its backup is reduced due to over-discharging or sediment deposit. In such cases, contact the customer care service for your battery. If your battery is within the warranty period, consider getting it replaced.

These are the steps to check the battery-

First, disconnect the battery from the solar panel connection and remove its screws using the appropriate tools. Then, carefully separate the battery to avoid any short circuit.
Turn on the multimeter and set it to DC voltage sensing mode. Measure the battery voltage and note this value.
Reconnect the solar panel wires to your battery and allow the battery to charge for at least 20 minutes to 1 hour.
After 1 hour, check the battery voltage again and compare it to the previous measurement.
If the battery voltage after reconnecting the solar panel is higher than when it was disconnected, then the battery is being charged by the solar panel. Otherwise, the issue may still lie with the wiring, battery, or possibly the solar panel itself.

2. Checking Solar Panel

If the solar panel is not providing adequate current and voltage to charge the battery, it will lead to charging issues. Therefore, it’s necessary to check the solar panel for any cracks or damage. Also, ensure the voltage of the solar panel is checked.

Here are the steps to check the solar panel:

Begin with a visual examination to identify any damage or cracks on the solar panel. If no damage is visible, proceed to measure its voltage.
Connect the multimeter probes to both output pins of the solar panel and point the panel face towards the sunlight. At this time, the output voltage should be between 10 to 18V DC.
The solar panel is considered to be in good working condition if the voltage is within this range. Additionally, test the amperage of the solar panel by connecting a 12V bulb and a multimeter in series.
If the voltage is within the normal range but no amperage is detected, the solar panel cells may have an internal disconnection or the cells may be dead.

3. Checking Solar Charge Controller

A faulty solar charge controller can also also prevent the battery from charging. Modern solar charge controllers, such as PWM and MPPT solar charger have displays that show errors. If a fault is detected, the controller will start beeping or blinking lights.

Here are the steps to check the solar charge controller:

The solar charge controller is the main unit for a solar charging system, so any fault within the controller will stop the battery from charging.
First, visually inspect the display of the solar charge controller to check the amount of amperage and voltage coming from the solar panel.
Then, determine the amount of voltage and amperage being used to charge the battery.
If there is any discrepancy on the charge controller screen, it indicates an error with the controller unit, which needs to be replaced.

4. Checking Connecting Wires

In many cases, solar power does not reach the battery when the solar DC cable gets damaged. To resolve this issue, recheck the panel wiring of the solar connection. You can also use a multimeter to check the wire’s continuity. If the wire has good connectivity, it is properly carrying power. Use a minimum of 4 square mm wire to connect solar panels to avoid energy loss through transmission. With this, you have successfully learned how to check if a solar panel is charging the battery. Next, let’s explore what might be wrong with your solar charge controller.

What is Wrong With My Solar Charge Controller?

After learning how to check if a solar panel is charging the battery, it’s time to delve into potential issues with your solar charge controller. A solar charge controller manages the power flow from the solar panels to the battery, protecting the battery life by preventing overcharge during daylight hours. If your solar charge controller is experiencing problems, there could be several reasons behind it. To identify the problem, you need to investigate potential causes, which could lie with the panels, batteries, wiring, or the charge controller itself.

Solar Charge Controller Not Charging Battery

If you find that your solar charge controller is not charging the battery, or if the charge controller displays 0 amps during charging, the issue could be with the wiring, input voltage, or photovoltaic panels.

Check if the battery is full, if the battery is totally or nearly full, the amps will drop low.
Ensure your solar panels are clean and placed in a properly sunny location. Dirty solar panels can result in poor power output.
Verify the input voltage. It should be around 18V, depending on your solar panel’s rating.
Inspect the wiring between the solar charge controller and the solar panel.
If the cause remains unidentified, perform a hard reset.
If the problem persists, it may be necessary to install a new charge controller.

The Controller isn’t receiving voltage from the solar panels

Apart from the solar charge controller not charging the battery, the controller might also not be receiving voltage from the solar panels. If you notice a moon symbol on your charge controller during daytime, it means your controller isn’t receiving voltage from the solar panels.

Firstly, disconnect the two solar panel wires from the back of your controller.
To measure the voltage across the two wires, use a multimeter. The voltage should be around 18V, depending on the rating of your solar panels and the amount of sunlight.
In the case of too low voltage, check the voltage from each panel with a multimeter. These should also be around 18V. If one panel shows a much lower voltage than the others, there’s likely a problem with that panel.
If all panels show an 18V reading, check the wiring for connectivity issues.

The Controller Isn’t Turning On

The solar charge controller might not be turning on due to wiring issues or incorrect system configuration. To solve this, rewire the system and, if it still doesn’t work, reset the controller. Following this, you might want to learn how to determine if your Renogy solar charge controller is working.

Also Read: Solar Charge Controller Settings

How To Know If My Renogy Solar Charge Controller is Working?

One of the easiest ways to check if your Renogy solar controller is working is to read the controller’s LED display. You can also use a multimeter to measure the power output. If there is no voltage or very low voltage, the controller surely has a problem. If you think your solar controller isn’t working as it should, you can diagnose the problem by trying a number of troubleshooting steps.

Also See: What Size Charge Controller for 200W Solar Panels?

How to Reset Your Solar Controller?

After exploring how to determine if your Renogy solar charge controller is working, let’s learn the process of resetting a solar charge controller. By resetting your solar controller, you are returning the controller back to its factory settings. If your troubleshooting methods have not worked, then resetting the entire system may help fix the issues with your controller. Make sure to perform the reset at nighttime. Make sure to perform the reset at night time. But if you want to reset your controller during the daytime, make sure to cover up your solar panels for safety. Additionally, follow the user manual instructions.

To Perform a Soft Reset-

First, press all four buttons on the front of the controller.
Hold these buttons for 15 seconds unit you see the charge controller resetting.
If this doesn’t work, proceed to do a hard reset.

To Perform a Hard Reset-

Initially, take the solar controller off the wall.
Now, disconnect all 4 wires at the back. The wires are- battery-negative, battery-positive, panel-negative, and panel positive.
Wait for 15 to 20 minutes.
Then, reconnect the battery positive and negative wires followed by solar panel positive and negative wires. After this, it’s time to learn about the reason behind the solar charge controller USB not working.

Why is My Solar Charge Controller USB Not Working?

The USB terminal output on your solar charge controller is designed to charge devices such as fans, phones, and other electronic devices. If your solar charge controller USB is not working, it may be because the controller isn’t reading the batteries’ voltage correctly, resulting in the USB port not being activated.

How to Check If Solar Panel is Charging Battery?