Maxxpower APU drains batteries

? Is the heat electric? Have you checked the draw vs what it is supposed to be pulling?
I can run my espar all night on low...

 

It should run longer than a few hours on heat. The system is different than the typical bunk heater system. It uses a heater to warm the coolant, then pump that coolant back thru the trucks heater cores. In my opinion, a better, more even heat than the blast furnace of the standard airtronics air bunk heater. The system is suppose to have 8 batteries, or at least the 2 different Maxxforce Prostars I drove that had that same system did. Perhaps one of the batteries in the other bank of 4 is bad, and is triggering the auto-start. It's either that or some bad battery cables or connections.

The down side of that system was the cost to repair. When it starts to sound like a truck stop powdered latte machine, it needs rebuilt, and it's expensive.

Another down side of the system is the a/c. During the summer months, it was rare to get over 4 or 5 hours on a charge before the truck started. But on heat, unless it's below 0, you should be getting what was advertised.

 

You probably should consider replacing the heater with a diesel fired bunk heater. Mine can go for a 34hr without needing charged.
But then again , i use Enersys Odyssey extreme batteries too. They're incredible and can't be found at a truck shop.

http://www.odysseybattery.com/design_advantages.aspx


http://www.odysseybatteries.com/batteries/pc2150s.htm


There is a local supplier that has better pricing in Chambersburg PA , named "Battery One"

 

The International system is a fuel fired system on heat side. It just heats the coolant rather than air. It actually is more efficient than the run of the mill airtronics bunk heater.

 

Those are really nice cause they keep the engine warm ...but they draw more amperage than the standard forced air , diesel fired bunk heater.

 

Did you figure out the problem ??

 

Bump. In case anyone else has the same issue.

I had a prostar with the Max power system. The experience I had with it was that if I had good AGM batteries I could go for 10 to 12 hours even in desert heat with the air conditioning. The heat never used as much power as the air conditioning. With the heater running I could go most of the day.
But again this was if I stuck with the high end AGM batteries.
When I replaced all of my battery's with regular deep cycles-I could not go for 4 hours without the truck running.
If you stick with a good quality battery like the North Star AGM-you shouldn't have any problems, unless something else is wrong.

 

Another tip for ac operation is that the truck already needs to be as cold as possible before starting the no-idle system. It was never designed to cool down a hot truck or recool it after the main ac has been off for a while. So it works best to run your main ac on max for as long as you can, then start up the aux system right after engine shut down for best results.

 

So Ive been using my MaxxPower 12 volt HVAC in the 2022 international. It’s been working pretty good up until a few weeks ago. It used to blow cold until the batteries ran down and the auto start would come on at around 12.2- 12.3 volts. The engine would auto start and run until the batteries were charged and then auto turn off and the MaxxPower AC would again stay blowing cold. The problem is that the AC now cuts off at 12.5 every time. The auto start does not come on. This is no good because I wake up totally drenched in sweat and it’s like an oven in here if it’s in the sunlight and 95+ degrees and Ive got the windows up.

So I figure there is a switch somewhere that has decided it wants to turn the HVAC off at 12.5 volts instead of below the 12.2 volts needed to auto start the truck. Ive tried shutting the main power disconnect for a few minutes and it didnt work. It’s got an Eaton 1800 inverter. Other stuff stays powered on below 12.5 volts just the darn AC keeps shutting off every time at 12.5.

Ive also checked the fuse at the battery post in the battery box between the frame rails. The fuses in all the fuse boxes look good and the relays i guess are good. The intake air filter has been changed regularly.

It just keeps shutting off at 12.5.

Any suggestions?