Enough Solar for conservative boondocking?

[Mariner14]

Hey Guys, I looked for the "Dumb Questions" thread, but didn't see it, so I'll post my question here.
I want to be able to boondock for 3-4 nights with my family of five on our 28 foot TT. I don't plan to need a lot electricity. I was thinking we would only need the furnace fan, a few lights at night, and water pump. The fridge, water heater and furnace all run on propane, so just their control panels would need some current as I understand it. I was thinking of adding a second battery, but for the same price I could get a small 50-100 watt solar panel to charge the one battery during the day. Wouldn't that be enough to keep us going based on our conservative power usage? What am I not considering?

Also, with just one small solar panel, I could just hook it directly to the battery to charge it, right? I wouldn't need a charge controller or whatever, right?
Thanks

[deadticket8]

I have something to say. RV.net is the just about the friendliest, most helpful bunch of strangers I have never met! I have gotten so much help here over the years. Happy Trails and Happy Easter everyone!

[Almot]

theoldwizard1 wrote:
Quick math. 100 watts is about 7A @ 14V (charging a battery take at least 14V). That will NOT recharge your battery especially if you have a furnace fan kicking on all night long.

Page #1: "I’m not even sure we’ll need the furnace".

That's why I am (usually) against solar as small as 100W. People don't factor the worst case scenario in, and then weather makes correction and what could've work, suddenly doesn't. Not completely intentionally, my solar was overbuilt by 40-50% for those loads that I am running. Additionally, uncertainty of a furnace draw was eliminated by eliminating the furnace in favor of propane heater, so the worst case solar scenario is still within the requirements.

[MEXICOWANDERER]

"The neighbor is making jokes that I don't have to buy a dog to pee on my trailer wheels, there are other people dogs doing this to me for free.

• Get fence charger
• Put landing gear or panel frames on rubber or wood
• Screaming dog makes a unique noise

[theoldwizard1]

Mariner14 wrote:

HQST 100 Watt 12Volt Off Grid Polycrystalline Portable Foldable Solar Panel Suitcase with Charge Controller

Solar Suitcase

Quick math. 100 watts is about 7A @ 14V (charging a battery take at least 14V). That will NOT recharge your battery especially if you have a furnace fan kicking on all night long.

[Almot]

Mariner14 wrote:
Thanks. Yes there are some cheaper ones on amazon as well that are separate panel and controller but I figured that would more trouble. More wiring and such.

There isn't more wiring with cheap off-brand controllers. But they are more trouble, yes.

Tell DW that the world doesn't end tomorrow (hopefully).

300W solar for $350-400 all including (not counting batteries that an offgrid camper should have anyway) might look like a lot of money, but it could let you camp offgrid indefinitely. Certain steps should be taken for energy conservation though.

Solar and batteries are long term investment. With only one short trip it won't pay for itself.

[Fiddlestix]

I have done nearly all my camping in the eastern half of the country. I have 2 group 31 duracells, 2-100 watt panels I put a piano hinge on them and have them slung in a 1 inch nylon web strap for carrying. I use an MPPT controller. I put rubber tube weather stripping on the insides of them so they don't bang around together and also don't scratch my camper top when sliding them up on the roof. I keep them in a childs an el-cheapo sleeping bag in the back seat of my truck when in transit. Cables, controller, etc are mounted in a battery box.

OK have dry camped in Acadia for a week. Very woodsy. Literally straight up sunshine and that's all. Ran the furnace, water pump, everything as if we were plugged in. Never in that week did I ever even come close to going under 12v. I've priced and checked and read forums on batteries solar etc. 200 watts solar and 220 amp hours is plenty. Also I must add that entire camper is led lighting.

[Mariner14]

Thanks. Yes there are some cheaper ones on amazon as well that are separate panel and controller but I figured that would more trouble. More wiring and such. And I like that this one folds in half. Easier storage when we’re on the road.
Dad doesn’t know enough about dry camping with batteries to admonish me. He’s only used it with FHU.

[westend]

Home Depot sells the Grape brand panels, on sale for $99. They also carry the Grape controllers that are a good controller for less than $50. This choice would be less than one of the suitcase solutions.

Good thing Dad is upgrading the batteries. I'm sure you're going to get at least a one sentence admonition about caring for them. I'd suggest to look at low cost campgrounds for a break from limited battery use and a chance to recharge/showers/laundry/ and things the kids can do.

[Mariner14]

With all these great products to buy to help us get off the grid, wife says, so the “free” boondocking is actually going to be the most expensive part of the trip? 🙂

For solar, I was looking at this one. Other recommendations for something with a controller for less?

HQST 100 Watt 12Volt Off Grid Polycrystalline Portable Foldable Solar Panel Suitcase with Charge Controller

Solar Suitcase

[Almot]

The neighbor is making jokes that I don't have to buy a dog to pee on my trailer wheels, there are other people dogs doing this to me for free 🙂

12 by 12 ft is not good enough. Dogs are all over, owner is on one end of the camp and dog - on another. Not that a headlamp would help in this case, either.

[MEXICOWANDERER]

The efficiency loss is like .00001% of the inconvenience of dragging a cord around. That lamp lights up a 12' x 12' area. So the dog taking it's human for a walk is no sweat. I've owned some mighty pricey head lamps and I consider them to be a toy. Used them for an hour to read. and get pretty near the pain of a migraine.

Yeah prepare a dinner then eat it like a pro spelunker. Cripes I did better than that hauling gear on pack saddles.

To each his own. I do not sweat using one amp hour of deep cycle for 7 hours of floodlighting. I gave Jesus a very pricey Underwater Kinetics "Light Cannon" for diving--12 (c) batteries. NiMH rechargeables. Different lamps, different lighting, different preferences.

[mike-s]

MEXICOWANDERER wrote:
You may want to consider lithium rechargeable LED lighting for tasking:

Uh, why? Recharging an LED flashlight is less efficient than simply using LED lighting in the first place. And that's ignoring the inconvenience.

[BFL13]

When the dog needs to poop after dark, you need to see to find it, to use your doggie bag. The porch/scare light is out of range for sure. Your flashlight in one hand the dog leash in the other, leaves no hand for the doggie bag. Headlamp! Problem solved!!! 🙂

[Almot]

In tent/car camping, headlamp is perfect. Shines exactly where you need, no waste.

Cheap emergency light: $1 lawn marker, solar-rechargeable. Cut the stake off, tie some shoelace to carry or hang upside down onto kitchen cabinet knob to make a supper. NOT much brightness. But it works, when AA/AAA batteries are done for.

Survival mode doesn't require big battery or furnace. Some tiny light to walk around without bumping into things, warm 3-season sleeping bag. This gets old soon.