# of watts solar system needed to MAINTAIN coach batteries?
Class A with 2 12 volt coach batteries. Want to maintain while not in use.
Forum Discussion
You can buy a 140 watt panel for less than it would cost to replace the batteries, or buy a full tank of gas, so why not get that size panel, and be able to enjoy the solar system?
SunElec.com
Look for a 12 volt panel and PWM controller. If you wire it directly to the battery, and use the factory installed disconnect switch, then the battery will still stay full anyplace (well except covered storage or a campground full of trees).
My motorhome used 0.8 amps 24/7 to run the CO meter and propane leak detector, and 1.1 amps (total draw) while the refrigerator gas valve is on, so about 0.3 amps per hour the refrigerator is running. . This works out to about 35 AH daily, or what a 120 watt solar panel will produce in one 'average' day, given there will be clouds, hot panels make less power than cold solar panels, ect.
So forget about the 10 or 15 watt solar panels for $30 - $45. They are in the $3 per rated watt cost range, and not worthwhile. The link above has some great aluminum framed 140 watt panels for $229 and many other brands for much less than that. . .
You can get 25' of UV rated grey romex at Home Depot, along with 2 feet of 2" angle aluminum. Cut into 6" lengths, you will have 4 panel mounts, that will keep the panel about 1" above the roof, so air will circulate under the panel, and keep it cooler (thus more power).
Good luck,
Fred.
SunElec.com
Look for a 12 volt panel and PWM controller. If you wire it directly to the battery, and use the factory installed disconnect switch, then the battery will still stay full anyplace (well except covered storage or a campground full of trees).
My motorhome used 0.8 amps 24/7 to run the CO meter and propane leak detector, and 1.1 amps (total draw) while the refrigerator gas valve is on, so about 0.3 amps per hour the refrigerator is running. . This works out to about 35 AH daily, or what a 120 watt solar panel will produce in one 'average' day, given there will be clouds, hot panels make less power than cold solar panels, ect.
So forget about the 10 or 15 watt solar panels for $30 - $45. They are in the $3 per rated watt cost range, and not worthwhile. The link above has some great aluminum framed 140 watt panels for $229 and many other brands for much less than that. . .
You can get 25' of UV rated grey romex at Home Depot, along with 2 feet of 2" angle aluminum. Cut into 6" lengths, you will have 4 panel mounts, that will keep the panel about 1" above the roof, so air will circulate under the panel, and keep it cooler (thus more power).
Good luck,
Fred.
