Solar install

Thanks for the info!!!

You want the controller as close as possible to the batteries. I would sacrifice a longer run for the PV cables than controller to battery cables.

18-20ft run - unless you forgot to include the height - equals to 11ft or 13ft box. Even with a rig that small, for the effort, I would install at least 160W panel. You won't regret it. Or 280W 24V single.

50ft roll of #10 MC4 cable (to make 2*25 leads) would cost about $30, - hardly a consideration.

Just be aware that some controllers do not like the battery disconnected before the panels for service or storage etc. A battery switch could let the smoke out of the controller. Review the instructions and installation manual carefully.

Thanks for the input. The way the roof is setup I have to mount the 100 watt panel to the rear of the trailer to avoid shadowing. Fridge vent is also at the rear with the converter next to it. PWM controller being utilized. Saves me around an 18 to 20 ft run of #10 once wired to the converter.

You're talking about connecting from the solar controller to the converter at the same post/connection that the battery connects to? Electrically, this will be the same as connecting it to the battery. The only difference, as Almot stated, is the distance and voltage drop from converter to battery.

Maybe you want to do this to keep from running such a long wire to the battery when the converter is right there and already has made that long wire run? Makes sense then if so.

Do not connect the solar directly to anything other than the controller - solar can put out 18 volts and batteries need 14, no more or they can way over-charge or worse. The controller will control all of this.

I would not call wiring to converter a "direct" way.

You connect it to converter output, from there it goes looong way to battery. The longer the post-converter cable, the more volts you lose (with PWM), and at some point voltage could drop too low to charge properly. With MPPT you might have enough volts but you start losing watts from the very first inch of cable (and MPPT without volt-sensing feature won't maintain correct voltage at the end of the long cable).

I recommend wiring from the controler to the batteries with a disconect switch close to the batteries.

boje wrote:
Can you go directly to the converter?

Yes

You can, if solar is small and controller is PWM. Make sure it won't get cut off like Mr Wiz said.