Solar panel charging starter battery

Hi all, 

I am fairly new to this so please excuse me if I am posting this in the wrong forum.

I have a 2014 Burstner T740 Nexxo Sovereign, I have been looking at the solar panel MPPT, it has a very handy App for a smart phone, all is great and the 2 x leisure batteries get charged, no problems there at all.

I have noticed that there is provision for charging a 2nd battery from the MPPT, my question is, can that second battery be the starter battery? Or would I have to disconnect the starter battery from the mini mainframe computer under the passenger seat each time I wanted to use solar power rather than EHU?