16month old Panels not charging enough

Sagecoachdriver · 10-29-2017, 09:09 AM

My Renogy 100 watt monocrystalline panels have been working fine charging up to 11.5 watts total for 16 months. But on our trip to the beach this week, they only had an output of <5.5 watts in full sun at noon. At home, I checked branch connections on the roof and the output at the fuse before going down the fridge vent and it was 20 volts. Did see the funny blue streaks like water marks in the panels. See photos below.
Checked at the controller and had 20 volts going in and 13 volts going to the batteries with only .5 amps after checking roof connections. I hooked up my Renogy 100 watt suitcase to the system passing it's controller and hooking it up to the system with an Anderson connector I installed when I installed the system to allow more watts if needed. The suitcase had an output of 3.6 watts which was fine considering it was later in the afternoon. But switching back and forth, I can see the output of the 2 roof top panels in no where near where it should be.
Going to call Renogy tomorrow and find out about the blue marks on the panels.
I bought them thru Amazon 16 months ago and not sure if I registered them for the 10 year warranty. Hope I did if that's the issue.
Going to do some more testing today. Any comments or suggestions?

ejohnson1144 · 10-29-2017, 09:15 AM

If you look at solar installations
panels are never pointing straight up . they are set at angle.
I wonder if the burnt out or shorted.

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Sagecoachdriver · 10-29-2017, 09:38 AM

My installation, like I said worked fine up til this week.

allears · 10-29-2017, 10:53 AM

Hello,

The marks are on the outside glass look benign. The outside glass is there to protect the panels from the environment etc and to dissipate the light better that shines through it. The outside glass is not electrically connected. Under the glass below those marks the panels look unchanged. But a shorted panel could be hard to see with the naked eye unless it was a big event, and it would take a very big event to create a mark on the inside of the glass, and yours appears to be on the outside. Also a large event should blow a fuse for the panel or one or both of the diodes on the back of the panel. You can get to those to measure by removing the cover on the box where the cables are attached. Once off use you meter in diode mode or resistance mode measure twice and the second time switch the positive and negative. One reading should be in the M ohm and the other very low ohm 1-2 if using the resistance mode. Also measure your fuses at each location in your system.

Another question, in your post you are saying watts when you mean volts or current when you are measuring the panels? What are you using to measure the panels and how are you taking the measurements? List: full or partial sun, time of day,the angle to the sun, is any shadows blocking even small parts of the panel during the measurements, meter setting, and placement of the probe tips. Renogy will ask the same questions.

Sagecoachdriver · 10-29-2017, 11:19 AM

Yes, I did mean 3.6 amps amps not watts. Waiting for the fog to burn off later this morning and recheck everything full sun no shade. I have a craftsman multimeter with built in clamp-on amp gauge. Going to do a thorough check. Those blue streaks seem to be under the glass and above the solar cell matrix. I would think that just because the panels have a 20 volt output the amps and wattage could still be lower should be.

HangDiver · 10-29-2017, 11:24 AM

Following...

Bluepill · 10-29-2017, 11:31 AM

Maybe try washing all the dirt off of the panels and re-test?

DonMcKay · 10-29-2017, 11:53 AM

Quote:

Originally Posted by Bluepill

Maybe try washing all the dirt off of the panels and re-test?

X2

WolfWhistle · 10-29-2017, 12:18 PM

What is the battery voltage, the output side of the charge controller? You won't see any higher current than the batteries need at what ever mode they're in. Near the end of absorb and anytime in float, the current you're reading might be normal. I agree with the others, keep glass clean.

Sagecoachdriver · 10-29-2017, 12:38 PM

Thanks, I am aware of all your concerns. Panels washed at the beach and again yesterday at home. House batteries are down about 25% at 46.6amps drawn per my Xantrex battery monitor. Controller output to batteries should be close to panel max of 11 amps when the full sun hits it. I have the battery switch for house 12v turned off as the solar controller is connected directly to the battery. Battery monitor still shows parasitic .2 amps drawn from other stuff like generator, slides and levelers than are on a separate cable going to the batteries. So currently with an overcast morning, all wire branches and connections to the controller cleaned, batteries down 25%, battery disconnect turned off, the battery monitor at the controller 13.3v and 3.4 amps. Let's see what happens when the sun comes out. Perhaps cleaning and reconnecting wiring did the trick!

TimVWulp · 10-29-2017, 07:08 PM

Hi it looks like you have some broken cells in the panel. The easiest way to check is with a infrared temperature gun. The cell that is broken or shorted will be much hotter than the other cells. When the silica solar cells brake or short out they will take the electricity made in the panel and make heat with it at the brakes in the cell.

Hope This Helps Tim

WolfWhistle · 10-29-2017, 07:25 PM

S, your 0.2 ~ 0.3 parasitic is same for me. I'm not familiar with your monitor, but if the charger is in float, at 75%, shouldn't you at least be in absorb? 75% would be around 12.35 volts, maybe your manual will shed light on the correlation between % and voltage. But, at which point I would want to see Bulk mode. If the sun is cooperating.

Villagerjjm · 10-29-2017, 07:51 PM

It looks like there is a condensation problem. I think the panels have lost their seal and are shorting out. Look for replacements!

Sagecoachdriver · 10-30-2017, 09:08 PM

Busy today and was it was overcast. But will call Renogy tomorrow. They are about a hour away with no traffic, so maybe I can take them in and get fast service.

Tom48 · 10-31-2017, 01:21 AM

Quote:

Originally Posted by Sagecoachdriver

Busy today and was it was overcast. But will call Renogy tomorrow. They are about a hour away with no traffic, so maybe I can take them in and get fast service.

Keep us posted on outcome. Both the problem as well as the warranty support.

I got to really test mine. I put an inverter on and used it pulling about 20 amps from the battery. My 380 watts of panels, flat on the roof like yours, were producing 17 amps plus at about solar noon.

Thanks Tom

Sagecoachdriver · 10-31-2017, 10:46 AM

Called Renogy this morning and spoke with Tech services. The blue streak is called a snail trail and is common and should not affect solar output. They recommended bringing it in and they will test the panels and replace if not producing proper output. I don't recall if I reregistered for the warranty but they said if I have proof of purchase ( a receipt) they will honor it.

1A Camper · 10-31-2017, 11:36 AM

2 thoughts
1 5.5 amp is about what one panel will but out. Disconnect one panel at a time to see if only one panel connected.

2 If your battery are fully charged 5 amp may be the most your battery will except. That will be all you will see. Turn on the water pump and see if current suppied increases

As a rule you never put a current meter across a power source as it will burn out the meter and damage power source but the solar panel will current limit and you can do the follow test.
Disconnect the solar cells wire from all circuits . Put a current meter across the 2 leads from solar cell (not the battery) with direct sun you should see about 5.5 amp from each panel or 11 amp if combined.

Sagecoachdriver · 10-31-2017, 12:49 PM

Still waiting for full sun before I do a re-test, overcast and drizzling. Last test was done later in afternoon, but 100 watt suitcase had 5 amp output, rooftop 6.5amps. Rooftop panels flat, suitcase angled towards sun. So panels may be OK, but need FULL SUN to test.

Sagecoachdriver · 11-03-2017, 08:30 AM

Weather is not cooperating, overcast and rain past few days. But heading east on Sunday for a 6 days and hope I can do a thorough test with the amp meter at the CG. If the panels are not producing the right volts and amps, I can stop by Renogy on the way home and exchange them.

garbonz · 11-08-2017, 11:16 AM

Quote:

Originally Posted by 1A Camper

2 thoughts
1 5.5 amp is about what one panel will but out. Disconnect one panel at a time to see if only one panel connected.

2 If your battery are fully charged 5 amp may be the most your battery will except. That will be all you will see. Turn on the water pump and see if current suppied increases

As a rule you never put a current meter across a power source as it will burn out the meter and damage power source but the solar panel will current limit and you can do the follow test.
Disconnect the solar cells wire from all circuits . Put a current meter across the 2 leads from solar cell (not the battery) with direct sun you should see about 5.5 amp from each panel or 11 amp if combined.

Or just bite the bullet and get a clamp meter, very useful tool if you are going to mess with this stuff. $25 and up.

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