[scottz]

Originally Posted by Greg10yes

I typically waited until we were on our way before turning it on giving the truck a chance to recharge the battery from starting reducing the load on the single alternator.

Your Victron DC-DC charger has a "delayed start" setting to allow the truck battery to recharge before starting to charge the RV batteries. Default is 2 minutes.

From the manual:

"Delayed start voltage delay (tstart delay): Recharge time for the starter battery during start level (delayed). Example: If the starter
draws 150A for 5sec to start the engine, about ~0.2Ah is drawn from the starter battery. If, during engine idling, the alternator can
only generate 20A, it takes 150A/20A x 5sec =37.5sec to recharge the starter battery. Default: 2 minutes."