Want to use my old battery to run the Dometic in the bed of my truck. Anyone have a feel for the bare minimum wattage solar panel that to keep the battery charged for running only the Dometic? Thanks!
I think 100 watts (might get away with 90) is the minimum you can get away with. Of course it depends greatly on if there is any shade, if you can position the panel to get direct sun at the right angle, what the ambient temperature is, and the actual condition of the battery. It also depends on the efficiency of the charge controller. So many factors, there are no guarantees. YMMV
My second battery is happy running without charging for a verified two and a half days, and the deep cycle battery is OK with that. When we are camping it is usually in the back of my TV with the charging setup from the car, and it is rare that we don't drive somewhere every couple of days. I did equip the box with an extra power point socket so I could add a solar panel to it easily, it's only money (and somewhere to carry the panels).
I use an 85 watt panel and it did fine even in Death Valley. Lots of sun vs lots of dometic run time and the battery still fully charged each day (according to the trimetric).
I have an 80 Watt panel and I think it is not up to the task. I haven't used it many times but generally prefer the analog (ice) cooler. Of course, there are variables such as ambient temperature, cooler set-point, UV exposure and other loads (like an APAP and lighting).
