I go against conventional thinking and use a solenoid for isolation, not a battery management system. I can state all the reasons for and against most systems and this is what I have used for decades with no ill effects. I will say though I don't run lithium's, nor will I ever. The benefit for me does not outweigh the issues. I'm sure people can chime in with their systems. I run a total of four batteries, two AGM in the vehicle and two lead acid in my trailer. Both systems are supplemented with solar. The vehicle's solar is only for keeping the batteries up while its parked and the trailer so it can be a stand alone.
Recovery times are based on the diffrent battery types, wire size/length and charging system. The average AGM/lead acid will draw around 40 amps when its low. This number decreases as it charges. This has to do with the chemical makeup of that type of battery. On my system "IF" all batteries were low, I would need 160 amps just to start charging my batteries. My system is designed for max flow with a 250 amp alternator. If I ran a smaller alternator, I would need some kind of management system to keep my alternator from overheating.
In the back of my head i seem to remember calculating the charge time on my old camper. Three AGM's in the camper and one for the truck. 200 amp alternator. Approximately 16 hours for close to full.
As you can see, there's a bit more that goes into it if you set it up properly. Mine is designed to fit my needs. If your charging lithium's, you need a good management system. If your charging system is not designed for two or more batteries the same may or may not apply to AGM/lead acid.
