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Solar Panel shows volts & powers LED but wont show amps or charge batt

I’m new to solar power so excuse my very poor knowledge here, I need help!

I’ve got two solar panels, small 25watt ones.

On checking voltage with a simple volt meter, it shows a good 12v to 16v depending on light hitting the panel.

No issues here.

If I directly connect a 12v LED light, it powers it fine, light comes on no problem.


If I connect the panel to my Charge controller for charging a battery, it reads NO AMPS and will not charge the battery.

This was with a cheap PWM charge controller, so I replaced that.

I now have an expensive EPEVER MPPT Solar Charge Controller 20A (TRIRON 2210N). This is a beautiful device, it shows watts, volts, amps etc on the display.

So I can see the amps from the panel is 0.00.

The volts is nicely sitting at 12-13v.

The indicator light for the pv shows its not active, not charging, but is connected.

Seems to indicate an issue with the panel maybe having a wiring issue or short (the indicator light is not on at all (should be green solid or green flashing to indicate connected ok and working or connected but not charging).

If that was the case, why would the panel power an LED light fine directly connected?

Would that not need some amps/watts to power it? How would it power the light if it was shorted?

I tried the same with the other panel, again shows volts but no amps. Powers an LED light directly without a problem (obviously not a great idea to power the light directly but I needed to test it somehow).

The panels are from separate providers, so they are not a bad batch as far as I can tell.

I’m very confused, and very new to this solar setup, help!

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Hi @hollett

What is the voltage of the battery under charge?

A LED doesn't produce any voltage but a battery does and effectively it is in opposition to the charging voltage, as +ve from the charging supply is connected to +ve of the battery, so the charging voltage has got to be greater than the voltage of the battery for current to flow.

If the battery’s voltage is high enough the controller may not begin to allow it to be charged, e.g. for a 12V car battery usually it needs to have 13.8V applied to it for it to begin to charge, although it might “trickle” charge it if battery voltage was only slightly less than the charging voltage but that may depend on the controller design

This link may help

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I'm not sure what the voltage of the battery under charge would be, since it wont charge ?

It's a sealed lead acid, sat at 12.4v with nothing connected to it.

But your thoughts make sense, it probably needs to have a higher voltage to be able to charge it.

I'm just confused at why the solar charger is not getting any amp reading from the incoming solar panel, even if the voltage is lower than what the battery needs. Maybe because like you say it doesn't have enough volts to charge so no current is flowing?

The pv shows as connected on the controller (eg sun and panel showing and volts are present), but no charging and green light is off. Which according to the manual means:

"No PV voltage or PV connection problem"

Maybe when its sunnier I can try again.



Double check the PV connections to the controller and make sure that they're not reversed.

Also measure the battery's voltage at the controller input terminals and check the wiring connection to the controller. Measure it at the controller's battery input terminals.

The manual says that if the battery voltage has to be >9V for the controller to be activated.

Has the solar panel got its own controller connected? It may be that it is preventing an output when the EPEVER controller is connected to its output as its resistance may be too low and the "onboard" solar controller is detecting this.

You may have to run directly from the panel to the EPEVER controller, bypassing its own mounted controller.

It would work with a LED light connected to the panel's controller because it is a more resistive load as seen by the panel's controller. Just a thought.


@jayeff Just a quick thank you to you for taking your time to reply to me, it was very helpful and its helped solve the my issue!

Now its a sunny day and I was able to figure out what was happening and your original reply was basically the right answer.

It seems the 'Over voltage' flashing light on my charge controller is equally an 'Under voltage' too.

So more suitably it should be called a 'voltage present but too high OR low' warning!

Once the voltage got to 13.6, the pv light stopped flashing, showed some amps coming in (only a few but the panels are not optimally placed yet) and the charge started to flow to the battery!

Battery is now charging (voltage is slowly creeping up), excellent!

Now I've proved it does all work, I need to properly mount everything in place!

Thanks for your time and help, its really appreciated.



Good to hear.

Depending on whether the installation is going to be fixed permanently in one spot or if it going to be "portable" in the sense that it can be moved location wise, roof of caravan or car perhaps, no doubt you have already checked this but bear in mind what the angle of the panels will be (if possible) so as to gain the maximum output from them.

There are calculators online that will help you determine the angle depending on latitude and longitude of the installation, summer and winter. Apologies if you knew this already.



You need 18/v panels or higher to charge 12V acid type


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