Originally Posted by peter
Hope this topic is ok on this thread. My question is can I drive all day in the sunshine using solar power( 95watts) with my fridge on or will it drastically reduce my batteries. Assuming there is nothing in the fridge that starts with P.Thanks in advance. Peter
That is actually a difficult question to answer. Some variables are: the size of your fridge, the air temperature, the efficiency of the circuit all the way from the alternator to the fridge, the capacity of your batteries, etc. Lots of hard to measure variables.
Starting at the fridge, using 12v option (as opposed to the propane option) will require somewhere around 200 to 300 watts. I don't have my manual handy but regardless, the fridge takes more than solar can provide. In theory, a running vehicle can make up the shortfall. But from reading reports on this forum, a number of folks say they end up with flat batteries after towing all day. So, what could be going wrong?
One problem, it is the long distance from the source to the drain (alternator to fridge). Skinny wire can cause a significant voltage drop. A bit of tarnish on the trailer connection can cause voltage drop (which is exacerbated at higher amperage). The trailer voltage regulator may be confused by the alternator voltage regulator. And the list goes on...
I plan to try the following some day. With a blanket over the solar panel and the fridge running on 12v with the door open (so you know beyond a shadow of doubt that the boiler is heating), measure the voltage at the dedicated fuse that goes to the fridge. Then, hook up the tow and and trailer plug and have a volunteer run the engine at 2000 rpm (for a solid output from the alternator). Measure the voltage again. If all is well, the voltage should go up around 1 volt - say from 12 to 13, or better. If you are not seeing a solid gain from the alternator, then you know that you will arrive at your campsite in the evening with drained batteries.
If you try this, please report back.
(And never, ever, put that "P" word in your fridge).