Is it worthwhile connecting to starter battery?

[Spade]

Hi all.
I have my van for the last 7 year's and the 12 volt set up that it came with, is two 110 ah lead/acid batteries with a unknown wattage solar panel (guessing 80/100 watt)
This is a picture of the solar controller.
I see it has an option to connect to the starter battery and I am wondering would it be worth doing?
is it just running a wire to the positive terminal on the starter battery?

 

[pappajohn]

Maybe need a second earth from a starter battery to common earth on controller.
If the existing 12v leisure uses the chassis as an earth then no need for a second earth

 

[Richard n Ann]

Hi all.
I have my van for the last 7 year's and the 12 volt set up that it came with, is two 110 ah lead/acid batteries with a unknown wattage solar panel (guessing 80/100 watt)
This is a picture of the solar controller.
I see it has an option to connect to the starter battery and I am wondering would it be worth doing?
is it just running a wire to the positive terminal on the starter battery?

Yes that's how I wired the Votronic up, the negatives are common from both batteries onto the chassis.

 

[Reallyretired]

Mine is set to give 30% to the starter battery. Keeps it fully charged while not in use.