Solar power problems

[Pedecanada]

So I have been trying to figure out what is wrong with factory installed from new Sunexplorer solar system. Everything seems normal but solar power is not getting to my batterys. The solar amp hours displays 0 when trailer is inside but when I take it out in full light it say charge on display not a number which mean the solar charge current is less than .20 amps so it trying to charge but at a very low rate what could be the problem. Do I need to replace pvcm250d in line charge controller it is located under head of bed in really tigh spot and what would it be worth. All the lights on charge controller seems to function like it working and makes a noise every 4 mins or so, Charge light and partial light are on controller when trailer is in the sun. Thanks for any help.

[idroba]

Unfortunately, I do not know your factory system and how it is designed to run. It is too bad it is in a difficult place to access. Here are the things I would do to begin with.

1. Make sure your batteries are good and fully connected, that is clean the terminals, both positive and negative. Do the lights and all 12 volt things work as they should when the rig is NOT plugged into 120 volt power? Make sure of that first.

2. Look for any fuses in the solar system lines. Check their continuity with an ohm meter to be sure they are good. Occasionally they will look OK but in fact have a hairline crack and won't pass power.

3. Look at the charge controller for fuses and check them.

4. Next check the panel output. If you can access the line which comes from the solar panels, and can remove it from the controller, remove it (mark it so you can re install it the way it was) and set your multi meter on DC volts. In sunshine, measure the Voltage across the line. It will probably be in the range of 17 to 18 volts. Then set the meter to Amps and measure the current flow from the panels directly across the meter (that is short the panels through the meter). You will probably have to change the lead location on the meter to measure Amps. This will not damage the panels at all, and will tell you if they are putting out power. You will probably measure over 6 amps and under 20 amps. Be sure your meter will measure 20 amps, some will only do 10 amps.

5. If it passes the tests in 4, above and measures about what I mention on volts and amps, and all your fuses are ok, and battery connections are good, I would next suspect the charge controller itself, as it is the only thing between the panels and the batteries.


Diagnosis of electrical issues by forum posts is an inexact science at best, but those instructions may get you started.

[Pedecanada]

Thanks for the hints and I will try those tests Idroba. Has anybody else had there factory display (charg) when solar charge amps is displayed.

[AirsDream]

I don't have your system ... have an aftermarket solar system by AM Solar, so I can't help directly. But if you're showing some charging but lower than you think ought to be the case, do be sure to check how clean your panels are. Just a little dirt or bird droppings or a leaf can drastically reduce output. For crystalline-based panels, even the shadow of a power line across them can take down the output to a fraction of of what it should otherwise be. An occasional panel cleaning can work wonders.

[Protagonist]

Dumb questions: Are the batteries already fully charged? Depleted? Somewhere in between?

If the batteries are already charged, then naturally the solar panel can't charge them any further.

BUT… If the batteries are too depleted, the solar panel still won't charge them. The factory-installed solar panels are good for a float charge to keep a battery charged, and compensate for small parasitic drains. The panel will not recharge a battery that has been discharged below about 80% charge.

The kicker here is that the charge controller runs off the battery. So, if the battery is depleted too far, the charge controller won't work. That means that the panel won't charge the battery. I ran into a similar problem with my Interstate, that has a factory-installed panel, until I did some research and figured out what the problem is.

Now, when I put my Interstate to bed in between trips, I park it with a full charge on the house batteries, and just use the panel to make sure it still has a full charge for the next trip.

[dkottum]

We have never run ours much under 85%, and it has been working fine. We're pretty skimpy on power use with it

My experience with this sort of thing is check the easy and obvious first, so would start with battery condition. They are at least four years old and may have been abused along the way (repeatedly run completely down).

doug k

[Pedecanada]

Ok think I found problem. Had my father in law who is electrician help me out. The panels are putting out 20 amps can see little spark when hooking up wires. Getting 5 amps to battery when over 13 volts. I left two fantastic fans run with trailer outside in the sun for 2 hours and solar display said 100 and did not lose any volts on battery. Put trailer in shop with fans running and display said 80% and we started to lose volt right away so that tells me they are working. Also when trailer was outside batteries went up 12.5 to 13 in 1 hour. The problem is the display panels is not displaying amps produced or total amp produced. Would be nice if it all worked but I am just glad solar system is working. Thanks for all the help this is a great Forum and makes owning a airstream much better since they are different than other trailers.

[idroba]

Your batteries may be on their last legs from what you mention. If they seem to charge up quickly, then discharge quickly when the sun is not present (you pulled it into the shop) that can indicate that the battery capacity is way down. They may seem to take a charge but have no capacity. That will also confuse your panel also, especially on total amps produced and/or used vs. what the battery capacity should be when new.

This again is just a guess on my part, but something to think about.