Rancher, They look fine to me too. However, the Blue Seas unit selected is a dual sense while the BEP unit selected is a single sense. That may or may not make a difference to you. BEP does offer a dual sense in the same form factor.
Say that you have solar and you want the solar to top off the truck battery too. As I understand it you need a dual sense version to do this. This so that which ever battery is being charged, the VSR/ACR allows that battery to reach it's full charge state before connecting the other battery to the charging source. Going down the road the alternator will charge the starting battery full first and then the relay/switch will close and allow the alternator to charge the camper battery. Next, you've been in camp for a couple of days when the sun comes out and the solar starts to charge the camper battery. A single sensing switch/relay won't detect this, but a dual sensing switch/relay will see it and will wait until the camper battery is fully charged before closing and connecting the starting battery to the solar system.
Once the charging source is removed (engine turned off, night time, etc.) either sense type will open and keep the batteries separate until another charging source appears.
'Raider, there are other viable options, but after much reading and consideration I have come to the opinion that an ACR/VSR is the best simple method currently available. Only a constant duty solenoid is simpler, but those come without any logic which forces the alternator to charge both batteries at the same time.
NTSQD, what you have described here is what my unit does.
Frank
