12V Solar Problem - No Charging.

[SolarGeth]

Hi There, New to the forum, sorry to bring you a problem with my first post! But im in need of some expert advice!!

Im running a basic 12v system in my van, a 100w 12v solar panel on the roof, connected to a solar charge controller, with a 100ah deep cycle battery and a small 12v lighting and charging system.

Basically, ive recently transferred my 12v solar off grid system from one vehicle to another and my solar panels just won't charge my batteries for some reason. I've run a system like this for 3 years now and havent had any issues with it. I just measured the voltage my solar panels are producing and im getting 12.8v. But when i attach it to my solar charge controller and measure the voltage across the connecters im only getting 1.5v.

Ive tried it with two different charge controllers and im getting exactly the same problem.

Could this be an issue with the connection to my charge controller? Im using exactly the same connections from my battery and load to the controller.

Im really tearing my hair out on this one. I just don't know enough about electrics to figure it out.

Any help or suggestions would be much appreciated.

Gethin.

[inetdog]

Hi There, New to the forum, sorry to bring you a problem with my first post! But im in need of some expert advice!!

Im running a basic 12v system in my van, a 100w 12v solar panel on the roof, connected to a solar charge controller, with a 100ah deep cycle battery and a small 12v lighting and charging system.

Basically, ive recently transferred my 12v solar off grid system from one vehicle to another and my solar panels just won't charge my batteries for some reason. I've run a system like this for 3 years now and havent had any issues with it. I just measured the voltage my solar panels are producing and im getting 12.8v. But when i attach it to my solar charge controller and measure the voltage across the connecters im only getting 1.5v.

Ive tried it with two different charge controllers and im getting exactly the same problem.

Could this be an issue with the connection to my charge controller? Im using exactly the same connections from my battery and load to the controller.

Im really tearing my hair out on this one. I just don't know enough about electrics to figure it out.

Any help or suggestions would be much appreciated.

Gethin.

You do have the panel in full sun for these tests?
With the panels disconnected from all other wiring you should be getting a voltage of 18-22 volts. If all you are getting is 12.8 there is something wrong with your panel.
Also, while it is disconnected from all other wiring put an ammeter between the + and - terminals of the panel. You should get at least .5A. If you do not, that is another sign that there is a flaw in your panel. Possibly a cracked cell, possibly a bad solder joint.
Did you flex the panels in the process of moving them?

PS: If your CC is like the majority, you need to connect it to the battery before you make the connection to the solar panel(s).

[SolarGeth]

Thanks for your reply, yes its in full sun, no shadows cast etc.

You mention about flexing it when moving it, thats something i hadnt thought about, its installed over a roof vent, the centre of the panel just comes into contact with the vent which is probably flexing the panel a bit. Causing the top to be ever so slightly convex.

Do you think this could have damaged the panel, or maybe the fact that its slightly convex means that it isnt producing the power it should?

The weathers clearing up tomorrow so in any case i think i'll take it down for inspection, check the cable joints and possibly try and raise it off the roof a few more inches, or remove that damn vent.

Thanks again for your help, helped me put a new perspective on it.

[Mike90250]

PV panels should never ever touch anything anywhere except for the mounting frame on the edges. The back sheet is VERY thin, and if it's scuffed and hermetic seal broken, or the cell underneath flexes and cracks, it's all over, done.

Another way to test, is to wire the PV panel directly to the battery, and over a few minutes, see if the battery voltage slowly rises ?

[Living Large]

Thanks for your reply, yes its in full sun, no shadows cast etc.

You mention about flexing it when moving it, thats something i hadnt thought about, its installed over a roof vent, the centre of the panel just comes into contact with the vent which is probably flexing the panel a bit. Causing the top to be ever so slightly convex.

Do you think this could have damaged the panel, or maybe the fact that its slightly convex means that it isnt producing the power it should?

The weathers clearing up tomorrow so in any case i think i'll take it down for inspection, check the cable joints and possibly try and raise it off the roof a few more inches, or remove that damn vent.

Thanks again for your help, helped me put a new perspective on it.

Do the handful of tests that were recommended, and report back the results. That would be helpful.

[Sunking]

Test the panel.