Overnight battery life and mini fridge?

Monitoring volts is really all a driver can do. APU's running in battery monitor mode can only monitor volts. It's not ideal but checking for available amps is not hardly an option for most unless they want to be constantly load-testing their batteries in their underwear with a pricey load tester.

 

If the volts aren't there. Neither are the amps.

You not going to have a lot of amps if the volts aren't there. And you need volts to push those amps.

 

Also might be worth mentioning that most newer trucks have battery drain protection systems that will start shutting off non-vital circuits as voltage drops and more then likely will shut off power to the circuit you have the cooler plugged into but again if it's only the cooler using power (outside of normal parasitic drains) then it will most likely run all weekend before it reaches critical point.

 

im just letting it soak in the way you said. WOW a virgin

 

I forget what its called but its a giant capicitor(spelling dont look right)that looks like a battery..It charges off your system and its only used for trk start..That way you keep the other 3 for internal power....
Im still running original batterys from 3 yrs ago now..Rarelt turn off the fridge other than when home in the summer..I have a 40 qt cooler on my jump seat,they suck a bit of power....In the winter it will freeze my food cause i dont idle much i like the cool..Come summer i cover up my windows to keep the sun out and put a blanket around it to help insulate till i get up..Mine isually shuts off after a cpl hrs..The voltage protect shut off everything in the bunk..

 

Mine sits overnight all the time and has zero issues. Even if I fall asleep with the tv on and have that extra drain. It's not that big of a draw.
I take 34s every other week on the west coast in a hotel and it sits through that and fires up fine.

I checked my voltage after my 34 (actually 37) on Sat morn in Klamath Falls, Oregon before I fired the engine and it read 12.4
Not sluggish whatsoever.
Alternator immediately shot to 14.2

 

That's cool, I've got one in the garage waiting to go into my little truck rv.

 

Them refrigs only cool a little compared to ambient temps so be very careful with food that can go bad quick, get a couple of gallon jugs of water and freeze them after taking a few cups out so you have a back up and just buy for a few days worth of eating.