Extra solar panel connection ,advice please

I have similar to your setup except that I have 360W of solar on the van's roof.
I also have an extra portable solar for the times I'm parked in the shade.

I have an Andersen plug on the draw bar that connects to the input from the solar.
So when the portable panel is plugged in it gives me another 140W of solar using the 30A regulator in the van.
The van has 2 x 120 Ah batteries.

The ute has a further 2 x 120Ah batteries and a 160W of solar on the roof of the canopy, I have a set of switches and cables so I can either link that solar to the van's batteries or link the ute batteries to the van ( giving me 480Ah of battery and a total of 560W of solar )

We travelled Aus last year and only had to run the Genni for the A/C in the Northern Summer.

Yes it will work, but it would be better if the second controller was close to the batteries.
Cheers,
Peter
OKA196 motorhome

Pepper
What type of solar controllers do you have on each setup? Are they PWM or MPPT regs?

With some systems the detection of battery voltage will be affected if it detects the pulses or different voltage level from elsewhere.
If you van has an MPPT controller which at least runs as MPPT while doing bulk charging you can use the van solar panels in series, provided the regulator is able to take the double input OC voltage. That means you will get half the current flowing in the panel side of reg but able to begin charging earlier and for longer as sun lowers. The MPPT section converts the higher energy level into just as much input to battery or moreso in some cases. The fact it has the potential, NO pun, to be well above battery voltage for more hours, means there will be significant greater charge being actually deliver to the batteries of the van.

I have recently done the above,with/to a friends caravan who could never get his batteries to be near or fully charged. Now with the double input voltage and MPPT controller of suitable rating, all over night loads are easily met and batteries are on float charge around lunchtime, instead of being low charge near evening.

You could simply plug the vehicle solar delivery taken from "before" the cars regulator, into the vans reg. ie in parallel with the van solar input and if the van reg can handle the additional amps, all van batteries should charge better.