ntsqd
Heretic Car Camper
The whole point of the ACR is to isolate the second battery when the alternator is not charging and the primary battery is not charged. Forcing the ACR to stay closed during cranking means that any starting current supplied by the aux battery will be routed through the ACR. This most definitely is NOT a good idea as these solenoids are not rated to handle starting current.
If you do not want to allow the ACR to be automatic then you're better off not getting one. Use a Cole-Hersee continuous duty solenoid instead. Wire it to activate with a manual switch or only when the ignition is on or however you wish to. Choose the solenoid with care. Some have a fairly high current capacity, others have a very low current capacity.
The bus bar is used on boats because they do not have a common ground. Can use it on a land vehicle, but excepting some particular circumstances it would be extra cost for not much gain.
Perhaps you'd get better advice if we knew all of your goals & uses for the system?
If you do not want to allow the ACR to be automatic then you're better off not getting one. Use a Cole-Hersee continuous duty solenoid instead. Wire it to activate with a manual switch or only when the ignition is on or however you wish to. Choose the solenoid with care. Some have a fairly high current capacity, others have a very low current capacity.
The bus bar is used on boats because they do not have a common ground. Can use it on a land vehicle, but excepting some particular circumstances it would be extra cost for not much gain.
Perhaps you'd get better advice if we knew all of your goals & uses for the system?