Portable solar panels are an essential utility for most people. It can be frustrating when your solar panel stops working for no apparent reason. And you desperately need to know where to start looking for solutions.
As a general case, portable solar panels stop working due to loose connections, dead batteries, or micro-cracks. A faulty charge controller cannot convert the energy from the photovoltaic panel to the voltage and current needed to charge the battery.

The solar panel is faulty
The very first item that needs to be tested is the solar panel itself. After figuring out if the panel works or not, other things can be tested.
When a photovoltaic panel is not working efficiently, it is not producing the amount of energy it is rated at. Or it does not generate energy at all when pandel is totally out of order. This can be caused by a few different reasons. You will certainly need to test the solar panel to figure out if it is working properly.
How to test a portable solar panel
To test solar panels, you certainly need a multimeter that can measure voltage. Right here are the basic steps for testing photovoltaic panels:
- Connect the positive output of the solar panel to the positive output of the voltmeter
- Connect the negative terminal of the solar panel to the negative terminal of the meter
- Make sure the solar panel faces full sunlight
- Check if the voltmeter must read close to the manufacturer’s rating indicated on the solar panel
If the reading on the voltmeter is close to the manufacturer’s rating when in full sunlight, then the panel is fine and functioning efficiently. It is a good idea to test the solar panel at noon when the sun is at its hottest and you will get the highest energy rating from the panel.
If the volt reading is between 50% and 100% of the panel’s rating, there can be a small problem with the photovoltaic panel. Because some cells may have micro-cracks in them or even some dead cells. If the volt reading is less than 50% of the manufacturer’s rating, then there can be a big problem with the panel. You may have to replace the panel in this case.
We recommend that you check the manufacturer’s warranty on solar panels, as most issues should be covered, and also the panels can be replaced free of charge.
The charge controller is faulty
A charge controller regulates the power and current produced by the solar panels to avoid the batteries from being overcharged and damaged in the process. Photovoltaic panels can easily overcharge and “burn” the battery, and a charge controller will certainly prevent this from happening. With the charge controller, you will additionally need a blocking diode that avoids the solar panels from discharging the battery during the night. If there is some fault or issue with the charge controller, it may stop the batteries from charging.
How to test a charge controller
To test the charge controller, you need a multimeter to measure volts and amps (current). Below are the basic steps to follow utilizing the multimeter to test the charge controller:
- Connect the output of the solar panel to the input of the charge controller as you would normally do
- Connect the charge controller to the multimeter measuring in amps/current
- You want to make sure your multimeter can measure the amperage output by the charge controller. In other words, the amp rating of the charge controller should be lower than the amp rating of the multimeter
- The positive probe of the charge controller is still going to the battery
- The negative probe of the charge controller is connected to the amp meter, and then the negative of the amp meter is going to the negative wire of the battery
By performing these steps, the current from the charge controller flows through the ammeter and can be measured. If you don’t measure at least 0.8 amps to charge your 12-volt battery, there must be a problem with your charge controller.
Dead cells or cracks in the panel
Microcracks start as small cracks in the silicone of the photovoltaic panel, but over time they grow in size and become visible. They are caused by defects in the manufacturing process or damaged panels during shipping. This is because the silver in the battery is easily damaged.
As the sun’s heat passes through the cells, it causes power losses that increase over time and cause that particular cell to stop working. Cracks in the cells will cause moisture to permeate the panel, and as moisture and electrical energy do not work well with each other, it will cause the panel to stop working. Just like hot spots, there is no way to repair a crack in a solar panel cell, and if the crack reduces its power output too much, you need to replace the panel. Many trusted manufacturers will certainly also cover micro-cracks in their warranties.

Hotspots
Hotspots are burn marks in a cell in the panel, which is caused by bad soldering or poor joints in the buzz bars of the panel. What happens is that power is going through the cell, but it finds a lot of resistance at that point, and as a result, it heats up. In some cases it can burn through the back of the panel. And in the process, if they’re installed on an RV or near any flammable material, there’s a real fire hazard. Unfortunately, no one can fix hot spots on solar panels. So replacing the panels is the only thing you can do.
Loose connections
All suitcase style portable solar panels have connectors between the two panels. These connectors are notorious for coming loose and rendering one of the two panels non-functional.
Check for any connections that may be loose or corroded, as they will render the panel non-functional. This may be a fairly simple fix. And also check for any connections that may be loose or corroded. As they will render the panel non-functional, which may be a fairly simple fix.

Doublecheck the wiring
Miswiring could also be the reason your solar panel isn’t working. Checking that the positive output of the solar panel is plugged into the positive input of the charge controller, and doing the same for the negative output and input. That can solve the problem of the solar panel not working immediately.
Check the alignment of the solar panels to the sun
For a photovoltaic panel to function efficiently, it needs to be in full sunlight. Optimal energy will not be produced if part or the entire panel is in shadow. You should move the Portable solar panels every few hours so make sure they are facing the sun.