Dry camping, batteries and slide out
I've tried searching for this but not having any luck. New travel trailer owner who recently went dry camping for the weekend. When I can't figure out is battery life. I have to deep cycle batteries ...
Forum Discussion
rbadger28 wrote:
What watt solar panel is required to be totally free of of shore power?
You need 110% of your daily usage to break even on battery usage.
Example:
As weekend camper, you might use 100AH per trip. Let's say that on a weekly basis, we have split the week into 3days camping/usage and 4days storage/charging.
To keep the battery at the optimal 50% or better state of charge(SOC), you want to begin the trip with a fully charged 200AH battery bank. Now to be ready for the next week, you need to replace that 100AH with 110AH of charging. The 110AH can be spread over 4days, or 110/4=27.5AH per day.
With solar, you must first know how much solar insolation, or power, is available in your storage location. Suppose your location is rated a 5. This means that you have an effective annual rating of5hours per day; 27.5AH/5H=5.5Amps. That is a panel rated at 5.5A.
There is one more adjustment needed to adjust for flat v.s. tilted panels. A tilted panel always faces directly at the Sun. There is a seasonal rating to account for flat panels being less able to harvest insolation into Amps. Using 70% will give a good estimate of your effectiveness; 5.5/.7=7.8A.
A panel rated at 7.8A Isc is needed to recharge the battery bank.
Now, what if it rains during the 4day charge period? :)
HTH;
John
