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[GMCnet] Power Adapter [message #325622] Tue, 31 October 2017 20:12
glwgmc is currently offline  glwgmc   United States
Messages: 1014
Registered: June 2004
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Senior Member
I can add a bit more to Justin’s very good observations. Solar panels come in a variety of flavors, some good in full sun, some good in partial shade. Most simply stop working when some portion of the panel is in shade - from a tree, the vent fan being open, your pod, etc. They will output the rated watts ONLY when conditions are perfect. For every 5 degrees you are off optimum sun angle you will loose at least 20% of the panel output. If the panel is dirty, all bets are off. Physical space is at a premium for our GMCs so plan carefully. Solar works really well for some, and not so well for others. It is FAR from a one size fits all application.

Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR

glwork@mac.com
http://jerrywork.com
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Message: 2
Date: Tue, 31 Oct 2017 10:09:49 -0600
From: Justin Brady
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Power Adapter
Message-ID:
Content-Type: text/plain; charset="utf-8"

Peer,
No worries man to each their own, but I can tell you (as someone who has 215AH of battery and 200W of solar) that you're going to struggle with lack
of power if you're camping for more than a day or 2 without hookups. To some that doesn't matter, but if you plan to stay for more than a day or so
off grid with an electric fridge, coffee maker, vent fans, lights, stereo, tv etc you will not have enough power.

200 watts seems like plenty, but you will only see 200 watts at noon in the summer time( and even then it's really only 170 or so for an hour in my
experience). Realistic output mounted on the GMC is more like 75 watts average over the daylight hours. When you consider that an electric fridge is
going to pull at least 75 watts, you've only broken even and not charged your batteries. Once you factor in the draw from your inverter for your
coffee maker, your cell phone chargers, your vent fans, your water pump and your lights you have actually drained battery even though it's been
"charging" all day. So on a good day you hit dark with a 75% charge. When you wake up in the morning you're now down to 50% or less thanks to the
fridge running all night. Since you're not really charging during the day you now need to run the generator to boost the batteries so you'll make it
to night 2.

If you really want it to work you need more panels and more battery if you want to be all electric.
That's why we went away from electric. The only electric we are pulling is the vent fan, the water pump, and the LED lights. (and an inverter now and
then for TV and cell phone chargers). The fridge runs on propane so no draw there, we do cook but it's all propane so no microwave or cooktop to draw
power. Even with this arrangement if it's cloudy for a couple of days in a row we need the generator to top up.

With solar anything that is a constant draw is a problem, especially overnight.

Not trying to be dismaying, just trying to help in your planning!
--
Justin Brady
http://www.thegmcrv.com/
1976 Palm Beach 455
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Jerry & Sharon Work
78 Royale
Kerby, OR
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