Solar charge to chassis battery

I am doing the very thing the OP wants using a Trik-L-Start. Super easy installation and does the job perfectly.

time2roll wrote:
Make it all automatic with a Trick-L-Start combiner. Everything stays isolated while in use. When the solar or converter is powered up it will send up to 5 amps to the chassis start battery.

http://www.lslproducts.net/TLSPage.html

X-2

Dusty

Make it all automatic with a Trik-L-Start combiner. Everything stays isolated while in use. When the solar or converter is powered up it will send up to 5 amps to the chassis start battery.

http://www.lslproducts.net/TLSPage.html

I maintain two Trojan T125s with a 30 watt panel mounted on top of my TT cover. $23 WindyNation weatherproof controller.

For maintaining batteries 200 watts is a lot. You should have no problem maintaining both house and chassis batts together all winter.
Bypass the solenoid that connect/disconnects the house and chassis batteries and keep the two connected all winter while in storage and let the solar charge.
Probably would be better to alternate charging the starting batteries and the marine or deep cycle batteries from each other as each will have different needs, but in the end the batts will be just getting a "float" charge anyway.
In my class c all I did was put a 15 watt panel on the dash board, parked facing south, and plugged that into a DC outlet that was connected to the battery (not through the ignition). This worked perfect for me, but I live far south in GA so had enough sun.

All motorhomes will isolate the house and chassis batts while the engine is off. They do this by using a big diode or by using a solenoid switch.
There is no reason for you to put a solenoid in while charging.
The Windy Nation system hopefully has a diode to keep the batteries from discharging back into the solar panels at night and this is the only diode that is needed for charging while in storage.

I have seen many motor homes have the solenoid right there at the chassis battery. You could literally jump over the solenoid. Make a wire with ring terminals on each end, long enough to jump over the solenoi. One end to the "out" going to the house batts, and one end on the "in" coming from the chassis batt and this will have the effect of the solenoid always being on.
Maybe someone else chime in if this would ever create a dangerous situation if the motor was cranked with the solenoid "jumped". I would just not ever crank motor wiht it jumped.

You could also, safer, take a 12v+ feed from the output of the solar panel, before the charge controller, and send it to the switch that turns "on" the solenoid, and this would turn it on in the daytime and off at night. Be-warned, though, that the solar panel will put out 18 volts, not 12. I am not sure if the solenoid will tolerate 18 volts or not. It might be fine, might not. That 18v could also back-feed into other vehicle components somehow...
Getting more complicated, you would pull the 12volts after the charge controller to the solenoid switch, but send the voltage to the house battery through a diode to prevent the house battery from always powering the solenoid.

Many ways to get to the same end. Your timer will work also.