How much solar to stick on a 22-24 foot "C"?
I am looking at class "C" rigs, but at best, they might have 100 watts on a panel. Realistically, for a shorter "C", how many watts should I be expecting to shoot for, on the roof? The battery bank ...
Forum Discussion
Hi BFL13,
I have a modest 256 watts of solar which I used to keep up an 875 amp-hours of battery bank. I separated the bank and was able to equalize, when the RV was in storage. Cost $1700.00.
Solar output, in leafy shade, is 7 amps from 90 minutes before solar noon to 90 minutes after solar noon. I don't have figures for when charging starts or when it ends in leafy shade--but if I stay off the inverter I don't run out of power (with the current house bank of 566 amp-hours).
Before that I had 30 watts of solar which serviced 250 amp-hours of battery bank. Cost $1700.00
I agree it is situational. But with the advent of the Grape solar controller (with temperature compensation) it truly is not needful for small to medium systems to have more than one controller. A second controller for portable panels is not necessary. Just a couple of switches that allow roof on / off and portable on /off and a connector for the portable panels.
An energy audit allows a better estimate of battery bank sizing. If one wishes to consume the batteries--then solar is 100% optional and probably not needed. If long life is wanted--then solar can really shine.
Now that I'm full time, I could put a 2000 watt system to good use. Before that, the 256 watts with the large battery bank meant I ran out of fresh water before I ran out of power.
For me, shore power has to be paid for as I am full time. I do agree that equalization can be done.
I have a modest 256 watts of solar which I used to keep up an 875 amp-hours of battery bank. I separated the bank and was able to equalize, when the RV was in storage. Cost $1700.00.
Solar output, in leafy shade, is 7 amps from 90 minutes before solar noon to 90 minutes after solar noon. I don't have figures for when charging starts or when it ends in leafy shade--but if I stay off the inverter I don't run out of power (with the current house bank of 566 amp-hours).
Before that I had 30 watts of solar which serviced 250 amp-hours of battery bank. Cost $1700.00
I agree it is situational. But with the advent of the Grape solar controller (with temperature compensation) it truly is not needful for small to medium systems to have more than one controller. A second controller for portable panels is not necessary. Just a couple of switches that allow roof on / off and portable on /off and a connector for the portable panels.
An energy audit allows a better estimate of battery bank sizing. If one wishes to consume the batteries--then solar is 100% optional and probably not needed. If long life is wanted--then solar can really shine.
Now that I'm full time, I could put a 2000 watt system to good use. Before that, the 256 watts with the large battery bank meant I ran out of fresh water before I ran out of power.
For me, shore power has to be paid for as I am full time. I do agree that equalization can be done.
BFL13 wrote:
On equalizing as a measure of solar required, most folks would never have to do that on solar. They can equalize other ways--such as when on shore power from time to time.
Why tell somebody they need so much solar to just go camping? All they need is a way to stretch out the time before their batteries get down too far before going home and plugging in.
There is no sense in advising people to put more solar on the roof and forget the portable solar, when their scenario is that the roof is under trees and the portable is set out where it can catch some rays.
If somebody is adding solar and wants to use a second controller with the added solar, instead of tossing his existing set-up, why not? It works.
It is all situational for what is the best advice.
