Wiring Solar closer to 12v fuse panel vs. directly to batts?

It's a 20 ft run to the batteries ..
Okay that means the converter wiring has a 20 ft or more run to the batteries

What size is the wire?
Is it bigger than what you bought?
Is it 6 gauge our is it 10 gauge ?
What size did you buy for this run?

Once the wire leaves the controller, it's at charging voltage, the longer the wire the more voltage drop, the smaller the wire the more voltage drop
In 99% of the time, there is loses that could have been avoided,
10 gauge wire is rated for 30 amps at 120v
But at 14v charging it will have too much voltage drop, and the batteries will rarely reach full charge..they will if the camper is not used for several weeks, but they won't when the camper is being used
Voltage drop means slower charging

I used bus bars to connect the solar controller, the converter, and the inverter to my batteries. Here's a picture of my DIY bus bar:



There are also commercial products that will do this type of connection/distribution.

You want to make sure that the wire size that leads from your batteries to your solar controller is large enough so that you are not losing too much voltage. The calculation for wire size revolves around amount of power and distance. Personally, I don't use any wire gauge smaller than 4 AWG to connect batteries. I paid good money for my solar system. There's no reason to throw away the power harvested by using too small of a wire. The alternative to spending $30 on wire upgrade is to lose harvested power continually, forever.

Voltage drop calculator

Go to Handy Bob's solar blog everything you need to now in one spot!!
https://handybobsolar.wordpress.com/

As stated, you need a controller; I wired mine directly to the batteries.

In my instance, I can isolate the batteries from the TT (using the cut-off switch) and still have the solar panels charging the batteries (or keeping them topped up during storage).

Gerry

Much helpful information about solar IN THIS FORUM THREAD.

Your panels output has to go into a controller, not directly to the batteries.

200 watts is about max for this. I do hope the wire to the battery is #6 or better.
What controller?

Seems to me you need a controller.

Panel wiring to controller & controller to batteries. The controller needs to be as close as possible to the batteries.

The Solar Guru's will be along shortly.