Forester RV prewired for Renogy what to buy

Wow, you left yourself open when you say a few hundred watts. You need to figure out what your AH use will be, or you hope it to be. Then you can firgure out how big of a system you want or need. Don't forget you must include batteries in the equation and of course how big a system you will need determines on how big your controller will need to be. You say your RV is prewired, You need to find out how it is prewired, meaning size of wire from where to what? Where is it terminiated, what type and size are your batteries. Renogy can cover any size you can dream of, my rule of thumb, get the most your pocket book will allow.

Another rule of thumb, here is the number of amp-hours you might consume per day:

6 Ah = living ultra-conservatively - you will want more

35 Ah = living very modestly, not a bigger RV

120 Ah = living comfortably, but not totally like you live at home.

Some say, the amp-hour capacity of your battery bank should be three to four times your typical daily amp-hour usage. And remember you only use about 50% of your battery when it is fully charged, before having to recharge it again. Lots of rules of thumb here   some also match the amp-hour capacity of the batteries to the watts capacity of the solar panels, but personally, I think you need more. I have 400w upgradable to 600w and I have 4 golf cart batteries in series/parallel giving me 440 Ahs, so I"m close to that saying   OH, I consume over 240 Ahs per day.