Solar maintainer?

[iamunique127]

We are awaiting our Calmark Cover made of the new WeatherMaxRV material and I'm unsure if the fabric will allow enough light to the solar panel to maintain our batteries over the winter. Our previous cover had a translucent white top which allowed enough light to pass through.

We have two six volt batteries which are quite heavy to be taking in and out. Last year's experiment of leaving them in the trailer worked out just fine. I turned off the battery disconnect so there was no draw and the batteries stayed topped up all winter.

I'm thinking a small portable solar panel bungee corded to the south-facing spare tire and connected to the batteries with alligator clips might be a good way to maintain the batteries. I've recently seen a 15W panel but it was intended for charging devices and only had USB ports. There are larger panels available but I'm not sure what I really need. We find our current factory-installed 160W panel meets our camping needs so I'm not sure we need a typical 100w portable.

Has anyone else has tried this type of solution.

 

[vermilye]

A bare (no controller) 15 watt or smaller panel could be connected directly to the batteries. Anything much larger should have a controller. There are inexpensive ones available.

You might consider the 100 watt panel even if you have a roof top panel. A portable 100 watt panel with controller will let you park in the shade or follow the direction of the sun (particularly useful in the winter).

 

[Ron in BC]

For years I kept my boat in the Med. Marinas used to provide a battery room where everyone left their battery to trickle charge over the winter. But, as you point out, batteries, especially larger boat batteries are heavy to lift out. I ended up buying a Siemens 5 watt solar panel and leaving it hooked up to two of my 3 batteries. I didn't put all my eggs in one basket. The next year when I returned the 2 on the solar panel were good and I couldn't revive the other one.

30 years old and still working. I stuck it on an old run down battery and even today, very cloudy and overcast and its starting to bring it up.

It doesn't have a controller.

 

[Selkirk]

My thought would be to look for a small, inexpensive, low-wattage panel (perhaps used) with the same open voltage rating as the rooftop panels. Then wire it into your change controller in parallel with the existing panels. This would be very easy if you already happen to have the optional external solar port installed on your trailer.

 

[iamunique127]

Thanks for the replies.

There happens to be a used Coleman 18W panel with controller available locally right now. From the sizes mentioned above it sounds like it should do the trick.

I was thinking of strapping it temporarily to the spare tire because that is the most south-facing part of the trailer when it's in storage and it would be vertical so the snow and ice would not adhere easily.

Right behind the spare is the battery vent, which I covered with wire mesh when the cover broke. (I haven't put the new cover on yet) I could easily feed the cable through there, which would be handy, or go around to the side hatch no problem.

I realize the vent is for hydrogen gas produced while charging LA batteries. I'd keep any connectors and potential sparks out of the vent area. Would that be safe or should I go around to the hatch?

If this scheme to keep the batteries charged works out I may instal a quick connect somewhere near the batteries next year.

 

[GinoandLinda]

Add me to the list suggesting using a small inexpensive panel to maintain your batteries. You can get a really small basic on for cheap, or you can spend a little more and get a 100w-200w that will serve as a supplemental panel while you are out camping. That's what we did with our previous camper which had heavy, lead acid batteries. We used a cable lock to secure it to the trailer. Never had anyone fuss with it.

 

[Ron in BC]

The 18W panel would be perfect. I wouldn't bother with the controller. When I left my boat batteries on the little solar panel for the first time I was a little worried about not having a controller. But it's a non-issue for a small solar panel and large batteries. Keep it simple.

I'd have zero concern running the wires in through the battery vent. Direct access, perfect.

Ron

 

[iamunique127]

Thanks, Ron.