What about solar panels?

I just hook to the batteries with alligator clamps. At home I hook up to a tender. Our TT is in our driveway.

eichacsj wrote:
I agree westend, thanks for asking. My condition is we 95% of the time are camping in the woods and we camp most of the time in the winter. So we are always in the trees so shade becomes the issue and that is why I have to continually go move it. I have a 40' 10 gauge extension wire to get it into the sun somewhere. I don't want to mount it as we like to snuggle up into the trees so the panel would be under shade.

So with my conditions it is just to much a pain to use it, I have only tried it twice. Now the solar sits in storage.

Do you have the charge controller attached to the module or is it next to the batteries? Do you connect the wires to the batteries with alligator clamps?

In AZ, in Winter, with a single module tilted toward the South (not moved) your harvest would probably be around 30-40 AH/day. That may not be enough to make any significant difference because you're using a lot of power. It will offer good storage battery care, though.

Because solar charging is dependent on many variables (amount of sun/shade, orientation for insolation, battery configuration, amount of power used, low DC voltage and amperage levels), the whole has to be configured correctly and connectivity issues need to be avoided.

I agree westend, thanks for asking. My condition is we 95% of the time are camping in the woods and we camp most of the time in the winter. So we are always in the trees so shade becomes the issue and that is why I have to continually go move it. I have a 40' 10 gauge extension wire to get it into the sun somewhere. I don't want to mount it as we like to snuggle up into the trees so the panel would be under shade.

So with my conditions it is just to much a pain to use it, I have only tried it twice. Now the solar sits in storage.

eichacsj wrote:
It is a 150w panel and trying to keep it facing the sun and it could not get the bats charged up before I needed them at night. We camp mostly in the winter so the furnace runs a lot, I also use a CPAP. The effort of getting everything out, setting it up chasing the sun with little value, is more a "pain in the ass" didn't know I could say it fully in the forum.

So I can last 3 nights on bats, fighting to keep them fully charged wasn't worth it. Now if they get to run down I get the gen out and give them a boost. 1 item, 1 pull and done.

As long as you have everything to enable the solar charging system, why not mount the panel on the roof and at least get the harvest that it can produce? At the least, it will shorten your generator run time and keep your batteries in top shape when your trailer is in storage.

If a single module is not enough, an additional module could be added to meet your power needs.

The only reason the above wouldn't work is if you always park in full shade and your trailer is stored indoors. Maybe you could post your conditions? At least the OP could then avoid those situations when he starts to use solar charging.

FWIW, I use a single 235W module and have 300AH of battery capacity. I run a small fridge and all of my entertainment gear with an inverter. Solar charging also takes care of the rest of the 12V system. I don't have any parasitic loads so don't use a disconnect switch. In storage, the module is tilted in Winter and keeps all of the batteries charged to the maximum.

It is a 150w panel and trying to keep it facing the sun and it could not get the bats charged up before I needed them at night. We camp mostly in the winter so the furnace runs a lot, I also use a CPAP. The effort of getting everything out, setting it up chasing the sun with little value, is more a "pain in the ass" didn't know I could say it fully in the forum.

So I can last 3 nights on bats, fighting to keep them fully charged wasn't worth it. Now if they get to run down I get the gen out and give them a boost. 1 item, 1 pull and done.

Your RV will consume about 35 amp hours a day just to run the CO meter, propane detector, and refrigerator. This is about what one 100 - 120 watt solar panel will make in a average day.

I would highly recommend a pair of solar panels in the 100 - 150 watt size. Above 150 watts, the panels are super large, and not really all that easy to mount to the roof between all the roof vents, A/C, antenna, and keep it out of the shadows of all these things.

SunElec.com is one of the places I would be checking prices. They had a 140 watt solar panel for $229 recently with aluminum side mounts.

You can cut some 6" long 2" angle aluminum mounts, drilling a 5/16" hole for a 1/4-20 bolt into the solar panel frame, and three holes 3/16" for #10 screws into the roof material. By coating all the bottom mounting surface with rubber roof sealant, it will act like glue to hold it to the roof. Also cover the screw heads to make it waterproof!

For wiring, I used #10 UV rated cable from Home Depot, it is grey and rated for UV, water and direct burial.

For a controller, I would recommend a cheap PWM controller, not the much more expensive MPPT controller. For the additional cost of the MPPT controller (I paid $500 for my 50 amp model back in 1999) you could buy a second panel and $20 20 amp PWM controller.

PWM = Pulse Width Modulation
MPPT = Maximum Power Point Tracking controller, that will take in say 17 volts that the panel makes X 10 amps (170 watts total) and will put out 13 volts X 12 amps. (156 watts total, but actually about 2 additional amps to the battery each hour.

Many will say MPPT is the only way to get maximum amperage, but my thought is 2 panels at $229 each and a $20 controller is much more power per day than a MPPT controller, and one panel for about the same overall cost.

Have fun camping!

Fred.

Unless you camp in the desert and use the panels for shading the roof from the direct sun, I do not see the advantage of roof mounted panels over ground mounted panels that can be moved as the sun moves; while the TT sits in the shade.

I have seen both solar and wind generators used on docked boats to top off batteries and feed phantom loads.

Unless you are going to leave the trailer for months, trickle charging won't serve any purpose.

Flatfive wrote:
I am thinking of getting a solar panel to trickle charge the 12V batteries of our TT. I would connect it when we're stopped and set up and disconeccted from the tow vehicle. What's a good one to get?

Trickle charge implies just for storage but then you want to set them up on the road while in use. What is it?

I recommend 100 watts minimum for the effort. 300+ watts if you expect to camp off-grid. And just mount them on the roof already.

If you don't want HandyBobs' rant try the 20 golden rules of solar, jackdanmayer.com Says the same thing as Handy Bob less the rant.