Inverter for truck

[DFB]

I'm looking at installing an inverter to my truck to power a twin tank air compressor. Talked to the inverter dealer today and he recommended this unit to run the 14amp Dewalt compressor I have

Robert what is the main need for using the compressor?

I started to entertain that idea of running a portable compressor unit powered by a 120v inverter a while back. I can use a small $40 400W inverter to charge my cordless tool batteries easy enough (Milwaukee manual recommends 300 watt min.) but I have an older Craftsman Industrial 6 gal pancake compressor and that has full 15 amp draw.

And I thought about taking that out in the apple orchard for a new project which quickly led me to start looking at inexpensive small generators instead of expensive inverters. First were the cheap $100 2 stroke units lightweight and portable but found most also didn't have the amperage either to support the average compressor draw of 13 amp or better. Next move up was 12.5 amp 4 stroke unit (trying to stay under $200) But that really didn't work either. And before you knew it what seemed like a cool idea started becoming costly fast

So while looking around I discovered there are a few low amp draw compressors available. Before that I didn't know there was such a thing. (I remember how my compressor would always trip the 15 amp breaker in my old apartment unit)

Dewalt has one with only a 2.6 amps draw DEWALT 1 gal. Portable Electric Trim Air Compressor-D55140 - The Home Depot
and there are a few others out there also.

Maybe the best compromise to do what you want to do and you could power that with a smaller (and less expensive) inverter unit.


I was kind of surprised using an inverter how quickly it can pull down your vehicle battery

For a modern camping unit today though I think I would want a decent generator.

I always got by on propane and 12v battery power with my old camper back in the day

 

[dieselcrawler]

The massive current draw an inverter in the 5000 watt range would would require an aftermarket charging system or dual alternators, or both.

The concept of 'the point of diminishing returns' comes into play... inverters up to 1000 watts for light, infrequent use, is reasonable. Bigger loads than that, for more than a few minutes, you need a stand alone gas motors generator.

 

[bd53bz2]

Another thing to consider is the wire size for a 5000 watt inverter. It will need 4/0 AWG copper.
Length to get to the bed might even require one size larger because of voltage drop!
Haven't priced copper wire lately but bet you are into the $300 range.

 

[Mendonsy]

The big problem with inverters is that it take a LOT of battery to run them.
We have an M-B Sprinter with a 3kw Xantrex inverter setup. It requires 4 deep cycle batteries and a 150 amp alternator. The Sprinter must be left on high idle for the alternator to keep up with the current draw.
You would probably be looking at 6 batteries and a 200 amp alternator to supply a 5kw inverter for any reasonable length of time..

 

[Walker1]

Just remember, all the 5,000 watts es that you take out of your electrical system has to be put back into it by your alternator that likely has about a 1000 watt capacity. So if you run your inverter for 15 minutes at near full load, you truck has to run for 75 minutes to recharge.

 

[Soundguy]

sound slike a gas powered air compressor is the answer here.

 

[k0ua]

Just remember, all the 5,000 watts es that you take out of your electrical system has to be put back into it by your alternator that likely has about a 1000 watt capacity. So if you run your inverter for 15 minutes at near full load, you truck has to run for 75 minutes to recharge.

With a 5000 watt draw and a typical 100 amp alternator and a single battery, I bet you could never make it to 15 minutes. I think most people don't realize how limited the electrical system on a standard vehicle is. Sure there are 300 amp alternators and multiple battery setups, but a stock electrical setup is pretty weak. A standard electrical system on a tractor is even weaker.

 

[Soundguy]

With a 5000 watt draw and a typical 100 amp alternator and a single battery, I bet you could never make it to 15 minutes. I think most people don't realize how limited the electrical system on a standard vehicle is. Sure there are 300 amp alternators and multiple battery setups, but a stock electrical setup is pretty weak. A standard electrical system on a tractor is even weaker.

yup.. that's north of a 400 amp load to get 5000w, and that's just on paper not taking into account conversion losses. I bet if you are really looking at a 5k load on the inverter AC side, you will be seeing near 500a load on the 12v side... the truck will think it has 2 starters turning over at the same time.

I agree.. 15 minutes at 5k load is hopefull!! might be easier on the batteries to just toss a piece of rebar across them.

 

[k0ua]

I love that rebar comment! Another thing is alternator ratings are also very optimistic. They are best case scenario's at high rpm when the alternator is cold. The output falls off when they heat up. These inverter threads come up every few months, I just chuckle. Sure small inverters can be very useful, big ones, not so much. Maybe for a couple of minutes. But not long term.

 

[Soundguy]

Yup, I don't like using past 80% rating on an alt for an extended time, and a 400-500 amp load on a standard alt is gonna 'electrically' look like a piece of rebar ..