# What equipment do I need to get my camper off the grid?

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So here is a link to my camper. It is the Silver Shadow 2009 High Line Model.

I would like to run two of the T30 model, its about halfway down the page.

http://www.kansaswindpower.net/bed_warmers.htm

Also would like to run my laptop and misc. electronics. Not all at once.

So my question is everything What size panel and other misc equipment do I need to to keep my battery 75%+ charged

• Solar Expert Posts: 5,183 ✭✭✭✭
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Re: What equipment do I need to get my camper off the grid?

well it (T30) draws 5 amps @ 12 v, what size and type is the battery?

KID #51B  4s 140W to 24V 900Ah C&D AGM
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Cotek ST1500W 24V Inverter,OmniCharge 3024,
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West Chilcotin, BC, Canada
• Banned Posts: 17,615 ✭✭✭
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Re: What equipment do I need to get my camper off the grid?

You start by calculating your loads. This is a bit more complicated in your case, as you'd have both 12VDC and 120VAC loads. It is also difficult to determine how long you'll use anything in advance, especially in a camping scenario.

But if we can get a handle on that .... (maybe Kamala can help out here!)

You can come up with a viable battery size (4 times the expected Amp/hr usage will keep you DOD down to the desired 25%). After that it's pretty simple to keep it charged: You need to supply a charge current of 5%-13% of the battery's total Amp/hr rate. As in: 50 Amp/hrs usage = 200 Amp/hr battery = 20 Amps charge current.

To get the panel size is another calculation. Basically 20 Amps * 14.2V charge = 284 usable Watts. Since panels usually only put out about 80% of their nameplate rating you'd really need about 360 Watts of panel.

One of the problems with camping is getting the panels aimed at the camp site. You may want a 'portable' panel set-up rather than fixed-to-the-roof panels. On that little camper there may not be room for all that panel either!

Please remember that this is a 'basic idea' explanation, not a precise calculation or recommendation.
• Posts: 6,290 admin
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Re: What equipment do I need to get my camper off the grid?

To keep that little guy going with a 360watt panel kit, Im looking at a very rough cost of \$2000 + to get started ???
• Banned Posts: 17,615 ✭✭✭
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Re: What equipment do I need to get my camper off the grid?

Money-wise you might find you're better off buying a small inverter-type generator. It could supply AC for running equipment and re-charging batteries during the day, allowing for 'quiet power' at night. This is often a more practical solution for campers than investing in large, fragile, and expensive solar panels.

The main problem is not having a good fix on your potential loads.
• Registered Users Posts: 11 ✭✭✭
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Re: What equipment do I need to get my camper off the grid?
So here is a link to my camper. It is the Silver Shadow 2009 High Line Model.

I would like to run two of the T30 model, its about halfway down the page.

http://www.kansaswindpower.net/bed_warmers.htm

Also would like to run my laptop and misc. electronics. Not all at once.

So my question is everything What size panel and other misc equipment do I need to to keep my battery 75%+ charged

You probably wouldn't need to run the heating pad longer than a half hour or so. We used to use one in our teardrop just long enough to warm up the bed and then turn it off. Teardrops are so small they don't get that cold unless you're camping in pretty cold weather. Your limiting factor will be your roof size more than anything else. You won't get a panel on your roof much larger than an 85watt or so, there just isn't that much room.

We could camp as long as we wanted without worrying about power with our 85 watt panel, Sunsaver 6 charge controller and a 120 amp-hr battery. Well, as long as the sun was shinning.:D Our loads included watching movies on a laptop, lights, radio, water pump, etc. The battery was still going strong after 4 years when we sold the teardrop.

Here's a link to our teardrop build page for more info...
http://home.comcast.net/~bdosborn/tear/teardrop.html

Bruce
• Solar Expert Posts: 5,436 ✭✭✭✭
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Re: What equipment do I need to get my camper off the grid?

Bed warmers at the best invention since sliced bread. It is the resistance heat source that I will use on my PV system (except a 25 watt soldering iron,, when the butane one is out of fuel!) But even at that, our queen bed warmer draws nearly 150 watts,, but only for about 1/2 hour per night.

To answer your original question,, KISS (Unless you are going to be full time in the camper!) Get the biggest panel that will fit on the camper, with a PWM controller matched to the panel. Get the biggest 12 vdc deep cycle that will fit into the battery compartment. Assuming that you connect to the tow vehicle once in a while (or to a gennie or grid power) to top up the battery, monitor the battery ideally with a battery monitor like a Tri-metric, or keeping a log of ah or wh used (estimated) so you know fairly well what percentage you have drawn down, (shoot for a max of 50% ideally only ~25%) and then bring the battery back to full charge every 3-4 days. You may go though batteries every 3 years instead of 5 years,, but in the end,, so what.

Tony
• Solar Expert Posts: 6,003 ✭✭✭✭✭
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Re: What equipment do I need to get my camper off the grid?
bdosborn wrote: »
Here's a link to our teardrop build page for more info...
http://home.comcast.net/~bdosborn/tear/teardrop.html

Hi Bruce,

I had lots of photos on top of text veiwing your web site with IE8.

Curious what was your final weight?
Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
- Assorted other systems, pieces and to many panels in the closet to not do more projects.
• Registered Users Posts: 11 ✭✭✭
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Re: What equipment do I need to get my camper off the grid?

Weird, it worked for me. Anyways, the trailer ended up weighing around 1500#, depending on how much stuff we had in it.
Bruce