My solar panel puts out 5v in full sun.

[Bultara]

120w normal output 13-17v any ideas?

[Sunking]

You have me confused with your thread Title.

Is it 5 volts or what?

[Bultara]

You have me confused with your thread Title.

Is it 5 volts or what?

Yes the output is 5 volts d.c. instead of 13-17 volts to charge my 12 volt battery.

[Sunking]

OK I understand now. It can be one of several problems. What is the battery voltage at say 3:00 in the afternoon?

[Bultara]

Battery voltage was 12.2 , P.V. voltage 5 . Measured at P.V. controller.

[RifRaf]

bultara hi, are you measuring the 5V with the solar panel open circuit, not connected to the controller? if so the panel must be damaged, to make such a low voltage the only thing i can imagine if something were bypassing all the cells, like a bypass diode that is faulty or short circuited somehow.

if not what is the voltage when not connected to anything? how many cells are in the panel?

[Bultara]

bultara hi, are you measuring the 5V with the solar panel open circuit, not connected to the controller? if so the panel must be damaged, to make such a low voltage the only thing i can imagine if something were bypassing all the cells, like a bypass diode that is faulty or short circuited somehow.

if not what is the voltage when not connected to anything? how many cells are in the panel?

Open ciccuit voltage in full sun, 5 volts. open circuit voltage in low light ie just before dusk, 17 volts. I have disconnected diode between + and- terminals of Solar Panel. As for number of cells, I am away from home all week, so , I'm guessing 60 cells .

[Sunking]

There are 2 test to determine the condition of a solar panel/
Voc and Isc. IF a panel pass these two test the panel is good.

[Bultara]

Voc=5v, Isc not sure how to measure

[Sunking]

Voc=5v, Isc not sure how to measure

Does not matter what Isc measures because a Voc of 5 volts is all you need to know, it is done and ready to go to the landfill.

[RifRaf]

to measure Isc you can briefly use your multimeter on the 10A scale by putting the test leads across + and - the same as you are measuring the Voc, Beware, this will burn out your multimeter fuse if you do it for more than a few seconds if the panel is rated for above 5A or so though as your panel is damaged should be ok, test the Isc in full sun and at low sun where you are getting 17V Voc, a clamp meter or proper ammeter is better to test with. You really want two meters so you can see the voltage at Isc as well as the current.

if you want you can bin the panel as suggested, however trying to fix it could teach you quite a bit even if you don't fix it, if you can get access to the cells and terminals so we can test a string at a time i reckon that when we find the issue you could bypass those spots and still get a usable panel, would be interested to see where it has failed

[Bultara]

Thanks Dereck , will let you know...

[Bultara]

Have 30 amp ammeter (analogue) will take the risk. Live near Coramba.

[RifRaf]

with a 30A ammeter you will be safe, if you near coramba could likely throw a stone to your place, is that in nsw?

[Bultara]

yes, near Ulong.