Solar panel charging truck

The detectors in my TC ran the truck battery down in a week.

With the panels flat on the roof, and the sun low in the sky, efficiency will be way way down. There will be several days in a row with no sunlight at all. If the OP only had 100W of solar, it wouldn't be able to keep up.

mkirsch wrote:
Assuming you get enough sun and keep the snow off the panels. Even then you're going to need a lot of solar to keep up because its efficiency is way down with the sun low in the sky and only out for about 8 hours a day.

Doesn't seem it would take much to keep batteries topped off with no real draw except some small parasitic loads . Battery Minders are only 1 or 2 amps .

Golden_HVAC wrote:
There are solar panel controllers with dual outputs for RV use. Basically it will send most of the power to battery #1, but when it is full, it will divert to battery #2 until it becomes full and it shuts off, or if battery #1 drops below say 12.9 volts, it will go back to charging battery #1 until it reaches say 13.4 volts, then will switch to battery #2 until both are at 13.4, then it will shut off.

Good luck,

Fred.

I've got one of them - mine is from CTEK. Its a combined MPPT solar controller and DC to DC charger - take power from the 7-pin trailer socket and the solar panel. Adjusts voltage and current to give optimal charging. When the camper battery is full it diverts the charge back to the 7-pin plug to keep the truck battery charged.

I did have to remove the relay that was fitted in the engine bay when I had the 7-pin plug installed that isolated the two batteries unless the engine was running.

Steve.

Assuming you get enough sun and keep the snow off the panels. Even then you're going to need a lot of solar to keep up because its efficiency is way down with the sun low in the sky and only out for about 8 hours a day.

Thanks for taking time to reply
Gaetan

Yes.
You have a Chevy so the +12v line in the 7 pin plug is always connected to the battery, even with the key off. The solar panel will charge your camper and truck batteries.
If you had a truck that the 12v line was disconnected with the key off it would not. This is one advantage to the Chevy set up. My solar panel charges my truck batteries as does my converter.

If there's no isolator between the truck and camper batteries, solar will charge both. Of course, the camper will also discharge both.

There are solar panel controllers with dual outputs for RV use. Basically it will send most of the power to battery #1, but when it is full, it will divert to battery #2 until it becomes full and it shuts off, or if battery #1 drops below say 12.9 volts, it will go back to charging battery #1 until it reaches say 13.4 volts, then will switch to battery #2 until both are at 13.4, then it will shut off.

Good luck,

Fred.

My solar panels keep my truck batteries charged.

I believe Chevys are not isolated but check voltage in the early afternoon.
s/b 13.2+ if charging.