Picking the right solar panel. Advice needed!

[thcguy12]

So I have done other posts about battery and solar and such but have one final question before I buy tomorrow and wanted to start a fresh post.

I need to decide whether to get a 40w, 80w, 100w, 120w solar panel. Some people tell me I need a lot. Some say not so much.

Here is what I would run. I have a deep cycle marine battery installed now.

1-2 days a month.
Camper kept in mountains. No hookups ever.

What we run:
--Lights at night only.
--Water pump after dinner for dishes. That's it.
--Heater at night if cold.

(No fridge. No showers. No tv. No charging items. No microwave)

What size panel do you think will be okay for charging the battery back up while we are gone or during day?

 

[Old Blevins]

Since you're mostly going to be using it to recharge the battery between uses - and it will have plenty of time for that - and you'll only be hitting the battery for a day or two at a time, I'd look at a smaller panel.  This is assuming you can place it where it will get several hours of sun a day.

Maybe: http://www.amazon.com/RENOGY%C2%AE-Monocrystalline-Watts-Solar-Listed/dp/B00DVPPFDS/ref=sr_1_1?ie=UTF8&qid=1431404395&sr=8-1&keywords=50+watt+solar+panel

This won't fully recharge your battery during each day of use, but should recharge it between uses.  Be sure all trailer draws against the battery are off while you're gone.  Maybe install a cutoff switch to make that easy.

 

[frankazoid]

if you are connected to the shore power when at home and 1-2 days is the only travels - you don't need solar at all

 

[Rene T]

if you are connected to the shore power when at home and 1-2 days is the only travels - you don't need solar at all

The OP stated that the RV is kept in the mountains and will not see any shore power at all. No hookups at all.

 

[Gary RV_Wizard]

Assuming that mountain location is mostly sunny, a  50-60 watt panel should be sufficient for this need. And if it isn't sunny, the size makes little difference. You have 28 days/month to recharge, so a low charge amp rate is sufficient.

The real concern is battery capacity (amp-hour) rating. You need enough amp-hours to provide 2 days of use. The battery you have should be fine for most purposes, but you may come up short if you need to use the heater very much. If you find yourself running low on power, add a second battery.

 

[Mopar1973Man]

Give you a clue. With a Cheap Harbor Freight 40w panel set I can watch TV on a old school 13" CRT TV all day long and still maintain a full charge state as long as I readjust the panel to chase the sun. This includes powering the A/D converter for the TV and this done from a 1,200w inverter. So 40w can do quite a bit. Like Gary said about amp/hour rating of batteries is going to be the big thing. There is going to times where the sun is not present like this morning we are totally overcast and rainy. So for those days your going to need the reserve capacity of the batteries or a generate to do the charging if the batteries are too small.