Is my solar panel knackered?

[c.smith1967]

Hi all I've been on the roof of my motorhome today and found the panel looking like the photo, I am guessing the panel is knackered am I right?

[littleharbor]

Not sure of the meaning of the term knackered but the panel looks fine from what I see.

I'm going to go out on a limb and guess this is a Kyocera KC120.

[c.smith1967]

I don't know the make until I get a chance to remove it on Saturday here is what I have found so far, voc 20v, Aoc 5 amps bright sunlight, when connected to pre tested controller output drops to battery voltage and output current max 0.1A (battery voltage 12.4v) connected panel direct to battery without controller with ammeter in circuit panel output max 0.1A

[c.smith1967]

Still to check connection on roof will do that Sunday weather permitting

[littleharbor]

Your battery could be full and not accepting any more current. You could have a loose high resistance connection. Try doing a short circuit test with your volt meter.

[Mike90250]

Your battery could be full and not accepting any more current. You could have a loose high resistance connection. Try doing a short circuit test with your volt meter.

CORRECTION
Try a amps test of your panel , using a properly configured amp meter rated for the expected panel amps. Then reset the meter before you put it away.

Never attempt a short circuit test of any battery, you will have vaporized copper plasma in your face and be very uncomfortable.

[littleharbor]

CORRECTION
Try a amps test of your panel , using a properly configured amp meter rated for the expected panel amps. Then reset the meter before you put it away.

Never attempt a short circuit test of any battery, you will have vaporized copper plasma in your face and be very uncomfortable.

Oops! My apologies. I wasn't clear in my thoughts to text conversion.. I ABSOLUTELY meant to test the panel connections, not the battery.

Good catch!

[c.smith1967]

I have traced the fault to 2 banks of 3 diodes that have blown, see picture, the manual states the following text.
9. BLOCKING DIODES Blocking diodes can prevent nighttime battery discharging caused and prevent modules from loss of array output and being damaged or destroyed by reverse current flow. KYOCERA modules do not contain a blocking diode when shipped from the factory, however most battery charging regulators do have this feature. 10. BYPASS DIODES Partial shading of an individual module in a 12 volt or higher "series" string (i.e. two or more modules) can cause a reverse voltage across the shaded module. Current is then forced through the shaded area by the other modules in series. By having a bypass diode, the forced current will bypass the shaded module in a series circuit, thereby minimizing module heating and array current losses. For 12-volt systems and higher: Each solar module junction box has a diagram illustrating the proper direction for the by- pass diode to be installed between two of the terminal screws (Figure 11, Figure 12). When the solar modules are connected as individual series strings first, and then these strings are connected in parallel, bypass diodes should be used in each junction box. This is the simplest wiring arrangement for most installations. At a minimum the bypass diodes must have the following electrical characteristics: