Small solar charger system...

Hi oakmandan,

You have to do an energy audit. There is one page on the spreadsheet to help you do that.

Solar for RV's is more often thought of as battery charging rather than directly running anything.

Let's take the water pump as an example. It may draw as much as 8 amps. But..........in 20 minutes of running it would empty most folks fresh water tank. That would be about 2.5 amp-hours of power. So in a day it may consume far less power than an 1141 bulb--which might be on for 2 or 3 hours.

oakmandan wrote:
Thanks for the info.... I though am a bit lost. How do I know how big of a solar panel I need for very basic use....light, fan, waterpump ?

There is a lot of info on RV solar on the web. Here is a place to start if you want to begin the learning process: link

You want to get some real deep cycle batteries (that usually means 6 volt) too and convert to LED lighting. LED lights can be had for a reasonable price from eBay if you are willing to wait for them to come from China. Just remember you want warm white in color.

I would advise 200 watts of solar for two batteries.

I'm going solar and will likely be putting 300 watts aboard going into my two Lifeline 6 volts AGMs (I want a bit more margin).

Do not take anybody's word for it however (including mine). Get educated so you can make an intelligent choice. I was ignorant about solar a year ago and have been learning a bunch. Lots of folks post about their solar systems big and small on the web.

100 watts per battery while camping is a starting point.
Lighting is a huge draw until you convert to LED lamps.

Here are some kits to compare:
http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Kits/c1_272/index.html

Basic hookup:
Solar panel -> Controller -> Battery

Thanks for the info.... I though am a bit lost. How do I know how big of a solar panel I need for very basic use....light, fan, waterpump ?

Hi,

Kits are almost always more expensive than buying individual components. A rule of thumb is between 60 and 150 watts of panels for every 100 amp-hours of battery bank.

Here is a link to the rather special spreadsheet that N8GS has created to help size solar battery charging systems!

Solar Spreadsheet by N8GS

We dry camp for a couple of weeks in Colorado every summer. We don't need our A/C. We run our fridge on propane and I do most of the cooking outside. We run the inside lights a little, the water pump for washing dishes and showers and that's about it. I'm going to get a system like this one before next year's trip. I have two batteries on our trailer.

Solar Charger

Whatever you pull out of the batteries you have to put back in.

If I don't always start out each day with a battery system re-charged to at least 90% charge state then my battery performance is bad and each day doing this it gets worse and worse. Eventually it will destroy my batteries.

My game plan would be to have enough solar panels to re-charge my battery bank back up to its 90% charge state each day so that I can have the advantage of full performance battery system...

That will be hard to do with one of those small low wattage solar panels that are only designed to trickle charge batteries when they are fully charged and just sitting in storage.

Just my thoughts

Roy Ken