Battery know how!! Tricks for the trade!

Xantrax inverter charger. 55amp charger but into the inverter. Plug it in when you get home or terminal and walk away. I close the curtains and leave my bunk heater on low when I'm home and nothing inside the truck freezes and the batteries are always getting worked so they are happier and last linger. Fridge likes being worked also.

 

You can have a system that shows that everything is fine till you put it under a heavy load....

 

I ment 14 volts when running, and that can drop depending how much electrical draw you have and how many amp alt, you are running some, but should stay at least close to 3 running.
All of my trucks have both a volt meter and amp meter, the amp meter while running will normally charge for a few minutes after using some battery power to crank it then return to 0 and stay there.
As far as the terminals. I used plain old grease for years , the idea is to seal it from air, or at least that has always been my understanding. I have found over the years that it seems like terminals do not corrode near as bad if kept tight and the batteries charged, it seems like those that get run down and stay down for extended periods corrode worse.

 

In the daytime. Yes. With nothing needed.

As you said. Under load. Run the headlights and you'll see droppage.

Loss of amps. Loss of volts.

But if the alternator is working properly. Even a no load will be higher volts.

Normal run at 14.3. Vs. 14.0 on a bad alternator.

Whatever the numbers be.