[Malaki86]

I was just thinking of a possible '90%' solution to keeping idle time down, as well as having enough power to keep comfortable in the truck in most situations. Just want your thoughts:

1 - Add a second set of batteries to the truck. I'm thinking about probably 4 1000amp deep cycle.
2 - Add a high-amperage battery isolator
3 - Add a bunk heater (Espar or Webasto) - hooked to Aux batteries
4 - Add fans to the top windows in the sleeper - hooked to Aux batteries
5 - Add a power inverter (1,500-2,500 watt) - hooked to Aux batteries
6 - Run a new power connector for a cooler - hooked to Aux batteries

The battery isolator would allow the truck's alternator to charge both sets of batteries while running. When shut down, the bulk of power pulled from the batteries would be pulled from the auxillary set, leaving the main batteries for starting the engine.

The bunk heater is self-explanatory - keep the truck warm on cold nights. With this setup, you could probably also run a 12v mattress pad or blanket as well, if needed.

The fans in the top windows would be for those times where it's not too hot outside, but the heat just builds up in the truck anyway. Open the front and/or bottom windows to let air in, which the top fans would blow out, sucking the hot air straight out of the truck at the point where the air is the hottest (heat rises, after all).

The power inverter would be for a microwave, coffee maker, whatever.

I'm thinking that total cost on this setup would be in the $1,200-1,500 range, with the bulk of the cost being the bunk heater. Installation could be done by an average mechanic, just as long as they understand the need for high-amp cables and such.

I'm thinking that a setup like this would allow for 15-20 hours of 'draw' from the aux batteries before they required the truck to be started for a recharge. Also, if the temps are below, say, 80 degrees, you shouldn't have any problem staying somewhat comfortable, even in direct sunlight.

So - what ya think? Sound like a workable idea?

[PrattTrucking]

Sounds like a well thought out plan, my 2 cents would be to consider a little bigger power inverter. 2,500 may handle the job, however it will get pretty hot.I had a 2,500 watt running a laptop, printer, and a fan. It seemed to strain at times and get super hot. I switched to a 4,000 watt. Aims or Wagan make good inverters. But yeah good plan, and a hell of a lot cheaper than an APU.

[firebird_1252]

if you watch ebay you can find a good deal on used APU's. just a thought. the way i figure it you can get one and have it installed for about $4k

[Oso]

Sounds like this: YouTube - ‪Idle Free Systems - System Demonstration Video‬‏

A Complete Electric APU System to Eliminate Idling

I have no idea how it performs

[Malaki86]

Hadn't considered a larger inverter, but that's definitely a good idea. Might also help, if there's room, to build some type of "wind tunnel" with a 4" fan blowing over it.

I talked to a driver with Prime that had that IdleFree system on his truck. He said it definitely works good, as long as you don't need A/C more than 8-10hours. After the batteries are fully drained (from running the A/C), it can take up to 15-20hrs worth of engine running to recharge it. I did like the idea of the shore power addition to it. Just not sure what all it would take to put in a transfer switch into the setup.

[allan5oh]

The problem is the batteries. You do not need 1000 CCA batteries, you want a large RC (reserve capacity) and a long life cycle. Currently there are no batteries out there that will last more than 2-3 years doing something like this. Even the best AGM batteries out there will wear out fast. Especially with heavy AC usage and constant draining of more than 75%. Non-AGM batteries won't last a year. Even after a few months storage capacity will decrease with both style of batteries.

With a system like this I would seriously consider a very high quality inverter, one that puts out PSW (pure sinewave) and also has shore power input. I would also consider at least a 200 amp alternator. Delco-remy 28 SI fits the bill. It is a brushed design, but I firmly believe these last longer because they run cooler (just put it beside a brushless design and you'll see why).

One thing I do not like about the idle-free battery system is the all in one heater. This is not an efficient way of doing things, a two piece system is much better. In fact the industry has pretty much shunned one piece heaters. First of all they actually use a lot of diesel, and they also use a lot of power since the factory sleeper fans are used. Not only that why do we need to keep the engine warm all night and day? It only needs about 2 hours of heat. My espar engine heater is 17,000 btu - 5,000 watt equivalent - and I've never needed to heat my engine more than 2 hours, even in -40 cold. I much prefer to the two piece system.

[Malaki86]

I've been in trucks with both the Webasto & Espar. Neither were tied into the OEM ductwork/fans. They just mount under the bunk, with 2 holes for the ducting. Running only the Espar in this Prostar for about 8 hours, with maybe 1-2hrs of using the laptop, the low-voltage alarm goes off in the truck, which shuts down all accessory power. But, I think that system is WAY to strict, because I've yet to have the truck so much as strain to start in even the coldest temps after the low-voltage shutdown has happened.

Even just running one of the small turbo-fans from the T/S's all night plus my laptop for a few hours will cause the alarm after 10hrs or so. Forget running a cooler when shut down.

All of this is just a thought to hold me over through my first truck. I'd love to get an APU right off the line, but financing both the truck and an apu right out of the gate is more than I want to do. I also won't do the multi-battery setup right away either. After a couple of months, I'll have a REALLY good idea of what the money will be like. Then, if I can afford it, it'll get an APU instead.

[Windwalker]

Saw one guy that had a box mounted to the frame, like the ones you use to store straps and tarps for a flatbed, but had an AC generator mounted inside. Summer time, he had a small window AC unit, and in winter, he would have electric heaters going inside. Didnīt get to ask him how long the generator lasted before he had to replace it. But, I did think about putting that on mine too.

[rank]

I have a Webasto and I run a coffee maker, microwave and laptop off my 1500 W inverter and the trucks 4 cranking batteries and have done it for 4 winters now without any starting issues whatsoever.

[firebird_1252]

Originally Posted by Windwalker

Saw one guy that had a box mounted to the frame, like the ones you use to store straps and tarps for a flatbed, but had an AC generator mounted inside. Summer time, he had a small window AC unit, and in winter, he would have electric heaters going inside. Didnīt get to ask him how long the generator lasted before he had to replace it. But, I did think about putting that on mine too.

i was also thinking of doing the same thing. but the way i look at it, is that by the time you get a good generator, ac, heaters etc its just a bit less then a apu. what i was thinking is: a 3000w generator (kipor) , a portable ac unit, portable heat and a battery charger. the one thing i havent figured out is how to get the vent for the ac out the window and make it so no bugs/rain/heat come in.