It all works the way it is supposed to thank goodness, but more amps could be useful at times depending on the scenario.
I have not yet tried the trick with an inverter on the starting battery powering a battery charger on the house batts. That method is available if parked and the engine is idling and means no change to OEM set-up. But not possible while driving so upgrading the OEM set-up would be needed for more amps that way.
I have a similar issue I think but have not looked into mine too much.. I will do more in warmer weather..
Remeber my aux battery in my truck is really a house battery. Its there for a truck camper, yellow warning lights on roof, 7 pin connector ect.. At this time all it does is the 7 pin... Thats it..
So like what I think you are saying is that battery does not recharge well?
Thats what I think mine is doing...
With a dead aux battery when I start the truck, the starting batt gets 40 amps. And all it did was start the truck.. Testing the aux battery I only see10-15 amps.. IMO that battery should be getting more amps. Its 145 amp alt..
I was thinking its a flaky connection in the solenoid isolator, but I test the amps on the wire coming to the aux battery right from the starter..
Maybe a bad starter connection. I can test this by removing starter connection and moving it right to the alt pos block..
So I know what your saying that you want more amps, or think it should be getting more amps just like I been pondering all year... But I have too many projects at hand... ha ha... and its -3f here in NJ... ha ha...
