Jean,
On my
Scamp trailers, I've upgraded the standard
battery to a Group 27 battery and used a small
solar panel (from Northern Tool) to supplement the battery in
boondocking situations.
By doing that, using only LED
lighting, a 12v Fantastc Fan, and running the
refrigerator on
propane, I've easily camped with no hookups for over a week.
As Dave also knows, it becomes a net sum game. If my fan and
LED lights pull 8 amp-hours
out of the battery per day and the sun (via the
solar panel) replaces 5 to 6 amp-hours per day,
I only wind up pulling a couple of amp-hours out of the battery per day.
Since the Group 27 battery has a capacity of about 100 amp-hours, that means that I can
camp without 110v "shore power" for weeks before drawing my battery below 40%.
I've used mono-crystalline
solar panels as small as 12 watts and 35 watts. Depending on
your daily amperage draw and the availability of sunlight for your panel(s), you may need to
use different wattage (larger?) panels.
If you are willing to consider even a small solar setup, you may have far fewer worries about
battery size/capacity.
Good luck! 😊
Ray
Sent from my iPad using
Fiberglass RV