Originally Posted by slloyd47
. I too question the distance of the charge controller from the batteries when it is put above the fridge. Any thoughts on this? .
RV solar controllers are just average electronic boxes.
A good Solar controller has a connection to the batteries that monitors the voltage, with no real load from its monitoring circuit.
A good solar controller also has a battery temperature probe.
That way a good solar controller can set the voltage it outputs to the battery to arrive at the correct potential at the battery. So it will up the voltage output so that the correct voltage is sensed at the battery terminals. Likewise it can increase or decrease the charge voltage on cold and hot days. So it wouldn't matter how far away from the battery it was.
The real concern with wire size is when powering a large inverter, when it can be sucking 20 or more amps.
With the solar panel on the roof and the trailer parked in the sun for weeks and not drawing down the battery, the battery does seem to get a good charge.
Replacing the amperage used in a day by the next day can be problematic if you use a lot of amps because at this time of the year a 150 watt panel has a hard time getting a good 5 hours of sun. You may only be generating 36 or so amps per day.
You need to live with the system, or maybe your old system to know the way you consume amps and how much sunshine is available in your area.
Maybe you don't need another 5% or maybe you do need another 80%.
I'm still trying to figure this out myself. Another panel would ensure I have the batteries fully charged before each night. And I haven't run out of power yet with just the single panel. Ah, but what if I was on a wind swept beach after a couple of days and nights just above freezing? I'd like to have another solar panel as insurance for that but the other 99% of the time it would be overkill.
I think the wire size from the controller into the battery won't change the suitability of just one panel verses two very much. It's too small of a percent.
It is rare that the controllers themselves can handle more than #6 wire. And I'm pretty sure the one installed by ETI specifies #10.