Solar Panel - storage

I have just put our 2011 Big Country 3250 TS to bed for the winter. Winterizing has been completed and because we live in a northern climate I also removed the two 6 v batteries and have them in my warm garage. Our unit has a 130 watt solar panel on the roof that now has no batteries to keep charged. Consequently there is a red blinking light that indicates a low battery signal on the solar panel display. Does anyone know if there's a way to 'turn off' the solar planel while in storage - there's no on / off switch inside the unit - or will this little red light blink away for the next 6 months? Does it matter?

Get that red light turned off! A parasitic load like that might run down the sun.

Throw a heavy tarp over it so it doesn't run down the sun.

I may not be much help as I leave my batteries in my trailer and let my solar panels keep them charged, but I see no problem in what you are doing as long as the wires do not touch.

There is no way to turn off a solar panel, big problem now for the fire service.

You can disconnect the wires to your controller, but the leads will still be hot. Best you can do is a heavy tarp over the panel

I think another solution is my controller has a fuse in it, if you remove the fuse the controller will not charge the batteries. This may or may not work with your controller.

Our controller of which we have just fitted is a Tristar MMPT Controller. It has a thermal curcuit breaker attached. We found that out when we had to turn the controller off in a hurry, as our guy that fitted it set it for 24 volt instead of 12 volt. It was cooking our batteries at 17.8 volts. Chuck & Elaine maybe you can also fit a switch or a thermal curcuit breaker to turn off your solar panels. I know you have taken your batteries out of your rig but at least then you won't have to worry. Cheers Paul

Chuck, You do not have to do anything. Your solar cells produce energy at such low levels of power that they are not likely to cause any problem. The most unlikely scenario would be "IF" a arc were to provide ignition to a flamable fluid i.e. gasoline. This is very unlikely. If this is still a concern to you, here's something to check. Most solar cell panels or grids have a water tight connector very close to the panel (in your case on the roof). These connectors unplug and disconnect the panel from the rest of the system. They are black, tight and have to be wiggled to pop apart, they terminate in a male/female configuation. Disconnecting will cause the circuit to be only as long as the panels pig tail and keep power out of your coach. Here's an interesting tidbit a solar panel producing 130 watts of power at 30 volts (DC) makes about 4+ amps. That's why the leads are so small. The average person could hold the wires and not even know it is live. The purpose of the regulator is to keep the voltage produced just over the voltage needed to keep the batteries charged (12.5 > 13.5 volts). Too much voltage will boil the battery fluid (electrolyte) and the battery will not work without the fluid. More info, it's an old wives tail that batteries cannot be left on concrete over the winter. Yes they can "IF" they are kept charged. I put them on a poly tarp, well ventilated and keep a Battery Tender attached all winter. This brand charger monitors the charge level volts and automatically applies a charge as needed. Not keeping the battery charged allows the PH of the electrolyte to go neutral and freeze. When a battery freezes it splits open and is no longer able to be used. You can buy a quality BatteryMINDer at most marine stores, Northern Tool sells them too.
http://www.northerntool.com/shop/tools/product_200332201_200332201?issearch=167981

What I was inferring was that maybe the code will require a disconnect switch on the roof at the solar panel(s) common wiring point feeding to the controller, even though the panels are low voltage DC. Again, power should be disconnected and protected as close to the source as possible. This is an RV solar discussion and I wasn't getting into solar systems intertied with the electrical grid.

RollingHome said:

Bill, The National Electrical Code (NEC) already states the protection needed, not only for fire reasons but for back-feed reasons. A large photo-voltaic (PV) panel grid is capable of producing lethal voltages. They produce DC Voltage which is fed to an inverter that creates AC voltage that can be lethal to anyone who touches the circuit. For this reason alone these units have to be able to be disconnected from the grid so a lineman does not get electrocuted from back feed. In fact this disconnect has to be readily available to anyone on the outside of the dwelling or commercial building. In addition there are other safeguards in grid connected PV units. However, in small stand alone (RV Type) PV systems the current is low enough not to pose an electrocution risk and this commonly assessable disconnect is not needed or required.

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Bill, the plugs (connected to the panels i.e. pig tail) I referrred to in an earlier post are considered a disconnect at point of origin or power creation.

RollingHome said:

Bill, the plugs (connected to the panels i.e. pig tail) I referred to in an earlier post are considered a disconnect at point of origin or power creation.

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My smallest solar panel has the plug Tom mentions. I just added a 15 watt panel to my motorcycle trailer - no plug.
When a panel is in the sun, it probably is easiest to think of it like a battery, has energy potential and you can't turn it off.

Easiest way to turn off our little panels is to just make up a heavy tarp to cover it.

As far as the big systems, disconnects are usually at ground level, the code doesn't address the panel potential yet.
Up to 600 volts DC typical running to the inverters. The inverters automatically disconnect the panels from the service in the event of a grid power loss.

Can't have panels supplying energy through the inverter back into the grid. No different then a standby generator.

I leave my panel connected to the battery 24/7/365. I always have a 100% battery even in the winter with lots of snow on the roof. 4 years now and no problems.

I don't see a reason to disconnect the panel for the winter. Even under a cover or snow it will still generate some curent, maybe not enough to charge the batteries, but once clear it will be back up to speed. And once the panels get over 10 watts or so they are equipped with diodes to prevent the batteries from draining into the panel.

My plans include roof mounted panels, but for this winter it may just be a 1 foot square portable (15 watts)