I’ve got a 30w foldable panel. I haven’t used it in a very long time, 2+ years probably. Do they go bad if not used?

I put it on the roof of my keep, beautiful sunny day, in direct sunlight and hooked up a Powerwerx watt meter.

I left it plugged in for over 15 minutes and the only source readings I got were:

0.04a
0.0Wh
0.04Ap
0.8Wp
0.000Ah
20.47Vm


There was nothing hooked into the load side but I was getting the following readings:

20.52V
0.8W

Or is there something wrong with the watt/amp meter?

I plugged in the cigarette port and hooked up a Battery Tender 12v inverter, it turned on immediately but wasn’t enough power to even notice the charging cord was plugged into my iPhone

Amps don't amp unless there's a load that eats the amps.

Voltage will be a bit high until there's a load.


Watts = amps x volts

The watt meter should have still shown some wattage from the source, right?

No. Watts is whatever is going into the load. No load, no watts.

I wonder why it didn’t kick on my cell phone charger

Was your cell phone plugged into it?

Yes. I had a powerpole USB charger plugged into the panel and then my USB charger plugged into that.

Was the cell phone discharged any, or already topped off?

Amps and watts will not be seen unless current is flowing.  They're not static things to just look at. They have to be happening to measure them.