It can be frustrating when your portable solar panel stops working for no apparent reason, and you do not know where to start looking for a solution.
As a general rule, portable solar panels stop working due to dead cells, loose connections, or micro-cracks. A faulty charge controller does not convert the energy from the solar panel to the required voltage and amps to charge a 12-volt battery.
The solar panel is faulty
The first item that should be tested is the solar panel itself. After determining if the panel works or not, other items can be tested.
When a solar panel is not working optimally, it is not producing the amount of energy it is rated at, or it does not produce energy at all when it is completely out of order.
This can be due to several different reasons, but you will first have to test the panel to determine if it is working.
How to test a portable solar panel
In order to test a solar panel, you will also need a multimeter that can measure volts.
Here are the basic steps to test the solar panel:
- Connect the positive output of the solar panel to the positive of the voltmeter
- Connect the negative from the panel to the negative from the meter.
- Make sure the panel is facing the full sun.
- The voltmeter should read close to the manufacturer rating that will be stated on the panel.
If the reading on the voltmeter is close to the manufacturer’s rating when in the full sun, then the panel is fine and functioning optimally. It is also advisable to test the panel as close to noon as possible when the sun is at its hottest, and you will get the highest possible energy rating from the panel.
If the volt reading is between 50% and 100% of the panel’s rating, there can be a minor issue with the panel due to some cells might have micro-cracks in them or 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, and it might have to be replaced.
It is advisable to check the manufacturer’s warranty on the solar panel because most issues are supposed to be covered and can replace the panel free of charge.
The charge controller is faulty
If you use a battery with your solar panel, you will have to incorporate a charge controller if your solar panel is rated at more than 5 watts for every 100 amp-hours of battery capacity.
A charge controller regulates the power and current produced by solar panels to prevent batteries from being overcharged and damaged in the process. Solar panels can easily overcharge and “cook” a battery, and a charge controller will prevent this.
With the charge controller, you will also need a blocking diode that prevents the solar panels from discharging the battery at night.
It is basically a link between solar panels and batteries, and if there is some fault or issue with the charge controller, it can prevent the batteries from charging.
How to test a charge controller
To test a charge controller, you will need a multimeter to measure both volts and amps (current). It is the only way to test if the charge controller is charging the batteries correctly.
Here is the basic steps to follow using 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 out of the charge controller to the multimeter measuring in amps/current
- You want to ensure that your multimeter can measure the amps that your charge controller is putting out. In other words, the amp rating of your charge controller should be less than that at which your multimeter is rated.
- 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 following these steps, the current coming from the charge controller is flowing through the amp meter and can be measured.
When you do not measure at least 0.8amp to charge a 12-volt battery, there is a problem with your charge controller.
Loose connections
All the suitcase-type portable solar panels have connectors between the two panels. These connectors are notorious for coming loose and rendering one of the two panels out of operation.
Check all connections that can be loose or corroded as they can cause the panel not to work, and it can be a fairly simple fix. Connections that are not making proper contact can cause a panel to be out of action.
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 sheet of the panel and, in the process, be a real fire danger when mounted on an RV or near any flammable material.
Unfortunately, someone can not repair hotspots on a solar panel, and the solar panel will have to be replaced. Most reputable manufacturers will cover hotspots in their warranty and will replace the panel at no cost.
Dead cells or cracks in the panel
Micro-cracks start as small cracks of the silicone of the solar panel, but then over time, they increase in size and become visible. They are caused by defects in the manufacturing process or damage to the panel when transporting. This since the silver in the cells is easily damaged.
As the sun’s heat goes across the cells, it can cause power losses, and these losses can multiply over time and cause the particular cell to stop working.
Cracks in the cells can also cause moisture to penetrate the panel, and as moisture and electricity do not work well together, it can cause the panel to fail.
As with hotspots, someone can not repair cracks in solar panels cells, and the panel will have to be replaced if its power output is reduced too much by the cracks. Most reputable manufacturers will also cover micro-cracks in their warranty.
Check the wiring
Faulty wiring can also be the cause that your solar panel is not working. It might seem obvious, but checking if the positive output from the solar panel is plugged into the positive input of the charge controller and doing the same for the negative output and input, can be an instant solution to your solar panel not working.
Check the alignment of the solar panels to the sun
For a solar panel to function optimally, it needs to be in full sun. If part of the panel or the whole panel is in the shade, it will not produce the optimal amount of energy.
A portable solar panel should be moved every few hours to keep it facing to the sun.
