Ducmonsta
New member
If the truck is running then both batteries should be connected to the alternator.
Depends on the dual battery controller/management system. Most isolators are designed to prevent over charging/discharging. Some systems do not "link" batteries in parallel.
For example, if all of your accessories are attached to the aux battery, then it (controller) doesn't allow the main battery to drain. If your vehicle is running and all batteries are fully charged, then it (controller) should isolate the batteries. Meaning, the alternator is only providing a charge for the main while the aux is isolated. The means less stress on the alternator. I think this is how the IBS system us designed. There are other features as well. Correct me if I'm wrong [MENTION=62008]limamike[/MENTION]. I know you have extensive knowledge with charging systems now with your trailer.
As far as the dual system I'm running (Kodiak), I have a solenoid that is manually switched to connect batteries or not. I leave it in the always on parallel. So my batteries are always connected when the vehicle is running. They are isolated when vehicle is off. The third position of the 3 pole switch allows for self jumpstarting.
























