Solar plus 1 engine.

[plumbob]

I am thinking a solar panel with a twin bank controller just to keep things charged when stopped, or at least help to.
Single diesel engine with 1 alternator. Split charge relay , 1 single 125ah LA battery starts engine, 3 125ah LA batteries for house.
Is there any reason the solar panel would need to be disconnected from the batteries when the engine is running??
Thanks

 

[Tranona]

No. Makes sense though to only connect solar to the house bank as that is the one that needs the top up when you are not running the engine. The engine battery should always be fully charged as its only job is to start the engine after which it is quickly recharged ready for the next start.