NEWS FLASH....TMC APU's

I saw a short nose with an APU at Weyerhauser in Plymouth NC. I said man that must be nice! driver said "it doesn't work. shop won't fix it"

 

I drive for a 70 truck fleet. Every truck in the fleet except for the one day cab quad axle has either an Espar or Wabasto heater installed. If it is above 10 degrees my truck is shut off and I am more then comfortable. You cant even use the darn thing on the high setting or it will roast you out of the bunk. They want us to limit unnecessary idling but they also give us the tools to be rested and happy. Some trucking companies are run by truckers and some are run by accountants.

 

Please show where I made an insult. I commented on TMC and you drive for Maverick and take offense. Makes one wonder where you really drive or not.

Second, after you spend a 34 hour break in sub zero no idling in Minnesota or in Florida high humidity and temperature, come back to the thread and be honest.

As far as useless advice, you border on it.

 

Hi everyone,
I'm not an experienced driver, but I am experienced with battery based electrical systems so I'd like to give my 2 cents. I'm going to base this on the "idle free systems" apu since I know the specs. Other apu's may have different results but they all have the same problems.
Battery based systems like the one from Idle Free Systems use AGM batteries to provide power to cooling and accessories. Idle Free Systems uses (4) 105 Amp hour, 12 volt batts totaling only 5040 WH. (WH=Watt hours=1/1000 KWH) Now the Trojan AGM batts they use should not be drained bellow 20% leaving us only 4032 WH if we do not want to damage the batts. The A/C unit pulls 40 amps at 12 volts and runs continuously in most hot weather. This draws a respectable 480 watts, which is pretty efficient. This is why the system fails to cool under very hot conditions. It's not a powerful system. Taking 4032WH(useable battery)/480watts(draw of ac) = only 8.4 hours. Already were at 1.6 hours less than advertized because we took the useable power of the batt, not the full batt. Now, going down to 20% regularly isn't great for the battery, but tons better then to 0%. You will however start to see the battery ware out as you use it more and more. This doesn't take into account any additional usage from Tv, laptop, fridge microwave etc so your actual run time will even be less, especially as the battery ages.
So what's the solution? Of course just add more batteries. Unfortunately more batteries mean more weight. At 430 pounds, idle free is already more weight than the average APU. To double the battery life it would weigh in at a whopping 816 pounds plus it would take a lot more space. An alternative is Lithium ion based batteries. They weight tons less and are much smaller. In an ideal world lithium would be the best solution. Currently I have not found a charger that will charge them from a truck alternator. They're much more sensitive to charging voltages then AGM. They also cost about 5 times as much making an APU cost thousands more. Lastly they have a bad habit of exploding on impact. If used in trucking they would have to be well protected in a fireproof box, which again adds to the weight.
So based on electrical knowledge and absolutely no experience using apu's, unfortunately I don't think there is any great way to store power efficiently enough to make battery based APU's a viable option. It may work for someone only stopping a few hours between loads, but the math shows it's not a good enough solution for OTR trucking.

 

DOT allows 400 pounds over your 80000 if you have an apu