ABOUT MY 2020 KW990 BATTERIES

Clean/tighten connections but batteries are probably junk

 

I’m wondering, if you have a bad battery that’s pulling down your overall voltage level, which is creating the load your APU is sensing?

With the crappiness of our roads and further crappiness of battery manufacturing, they just don’t last anymore. I’d pull all of them, rotate them through a charger, then, have them all load tested. You’ll quickly find the bad one. If you don’t care to do that, just figure on replacing the whole bank. Never replace just one at a time.

As a side note, you may research capacitor technology. A buddy recently installed one and says it’s ability to crank is otherworldly. I don’t know enough about them to authoritatively speak about them. But, I think, they’re worth looking at, if for nothing but looking at all options.

 

Sounds like your batteries are crap. If they are original and it’s a 2020 then they for sure are. Unfortunately the oem batteries your lucky to get 2 yrs.

 

Batteries are 12v, alternators charge at 14v. Of course your voltage isn’t going to show 14 volts with the truck or apu off.

 

Spend the money and replace the batteries. You'll thank yourself later. Especially when you hear of, or see someone broke down on the side of the road because they took a chance with their battery that gave them the warning sign of a hard start but they felt it could go just a little longer. Look at them now, broke down and costing them down time and more money.