Using RV inverter as power source (boondoging, no batteries)

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Toaster

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Wondering if I can use my truck, with its battery when it runs, as a generator, and what the average TT inverter will handle? If I want to run power tools, I think I may need at least 600 watts.  :'(
 

mrschwarz

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It doesn't matter where the 12 volts comes from. Power is power. It all depends on the truck's ability to generate power. Is your inverter powerful enough for the power tools? Do the tools need pure sine wave or is modified sine wave sufficient?
 

Mopar1973Man

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Ok simple way to look at it...

Find out what your maximum amperage output of your alternator is. Like on my 2002 Dodge Ram its 120 Amps. So now do a bit of math.

120 Amps x 12 Volts = 1,440 Watts worth of power your truck can provide.  So if I was to think of using a inverter for a power source I wouldn't exceed 1000w or maybe 1500w inverter to protect the truck from damage.

But I can tell you now you got to look at the loads within the RV and how much wattage you need to survive. This will vary from RV to RV and person to person. Like I know my Jayco can work on a 2Kw portable genny just fine for little things. But no A/C, water heater or Refrigerator (AC).

Now also consider your battery Amp/Hr rating too... Most engine batteries are rather low in the Amp/hour rating and will not last very long at all without the engine running and the alternator charging.

Give you a feel for house applications. I've got a 4Kw inverter here in my stick house, 820 Amp/Hrs of batteries (1,000 pounds of lead acid batteries) which will provide...

4000w / 24 Volts = 166 Amps Draw (Full load)

820 Ah's /  166 Amp = 4.9 hours of power. (Without any external charge)

At least you can use my math to do some figuring and thinking about what your going to do.
 

Molaker

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mrschwarz said:
It doesn't matter where the 12 volts comes from. Power is power.
Not entirely true.  The invertor should be as close as possible to the battery and with large gauge wire.  A 120vac power tool drawing 5 amps will consume about 600 watts which will require about 50 amps from the 12v battery/altenator.  Consequently, 6 ga. wire at minimum s/b used connecting to the battery and no more than about 4 ft. long.

If you are just wanting to have an inverter at the truck to run power tools and not necessarily installed in a TT, then your best bet is to mount it under the hood with short large gauge wires.
 

warsw

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Mopar1973Man said:
120 Amps x 12 Volts = 1,440 Watts worth of power your truck can provide.  So if I was to think of using a inverter for a power source I wouldn't exceed 1000w or maybe 1500w inverter to protect the truck from damage.
A larger inverter won't damage your truck but if you pull more than your alternator can put out and run it long enough your battery will eventually go dead.

I have a 1K-watt inverter connected to my truck battery and it does a really good job of running power tools. You just don?t want to run something that is too much for the inverter.
 

Frizlefrak

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I have to ask....if boondocking, why not just pick up a cheap 3000 watt generator from Pep Boys?  They go on sale for about $239 from time to time.  If it's just to run power tools, it will run just about any of them.
 

Toaster

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I might need one to run a drum sander + vacume at some point, so probably a 4-5000. Right now I just need basics, maybe some recharge ability, vacume, small fan to suck out dust. etc.

I would be running the engine for this. It has 120V outlets in it, just don't know enough about electrical just yet.
 

Lou Schneider

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Note that your alternator makes it's rated current at high RPMs.  With the engine idling, you have significantly less output.

If you pull more current than the alternator is putting out, you will drain your battery.  But inverters have low voltage cutouts, so they'll shut off before your battery goes completely dead.

That's also why you need short, thick wires between the battery and the inverter.  If the wires are too thin or too long, they'll lose voltage when you pull a load through them so less voltage reaches the inverter.  The low voltage cutoff will activate and the inverter will shut off even if the battery is fully charged.

If you're running power tools intermittently, on for a couple of minutes then off for a few, the alternator will refill the battery when the tools aren't drawing power.  Just leave the engine running for a bit.
 

Molaker

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Toaster said:
I might need one to run a drum sander + vacume at some point, so probably a 4-5000. Right now I just need basics, maybe some recharge ability, vacume, small fan to suck out dust. etc.

I would be running the engine for this. It has 120V outlets in it, just don't know enough about electrical just yet.
From this, are you talking about a plan to use a TT as a workshop?  If so, a portable generator would be your best bet, but you could temporarily power (120vac) off an inverter connected to your truck, but as stated, the inverter s/b as close to the truck battery as possible.  The TT will typically have a 30 amp power cord which has a unique plug.  However, it can be adapted to plug into standard 120 vac 15/20 amp outlet.  You could connect this plug to your inverter, but you would want to make sure everything that uses 120 vac is turned off in the TT - except for the 120vac outlets you might want to use and keeping in mind your power limitations.
 

Gary RV_Wizard

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...and what the average TT inverter will handle?

The average TT doesn't have an inverter at all, so what yours will handle depends on what inverter you buy and install.  Few power hand tools use more than a couple hundred watts (exception would be anything that makes heat, e.g. a heat gun). Bench tools, e.g. the drum sander, will be more, dpending on the size of the motor.  A 1000-1200 watt inverter should handle your tools nicely, but it needs a lot of 12v power to do so. For example, 600 watts needs a steady 50+ amps @ 12v.  That's probably 50% or more of your trucks alternator max output and the engine needs to be running at substantial RPMs to produce that much. Idle speed, or even 1000 rpms, won't be sufficient. I'll hazard a guess that it may take 1500-2500 RPMs, but it varies by alternator size and design. An alternator upgrade for the truck may well be needed to do the job effectively.

Since hand tools seldom operate continuously, it makes more sense to provide a battery bank that can provide amps for peak power loads and store the energy from the alternator, which then can run at a lower, continuous output. Better yet, a small generator would do the job without any inverter or truck alternator at all. Something like the Honeywell 800 or 1000 inverter-generator would be ideal for power tools of all sorts. They are light and very quiet when the load is light.

http://www.electricgeneratorsdirect.com/Honeywell-6064-Portable-Generator/p6685.html
 

denmarc

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All things considered, I have to agree with the idea of maybe purchasing a small genny.  Your boondocking so the local critters aren't going to give a rat's butt about the noise of a genny sold at one of the big box stores!  Save the fuel money on running a V8 engine (an assumption) in your truck to operate the alternator just to charge up a battery and run an inverter.  A small genny will run for hours on just a few bucks worth of gas depending on length of use.  If that is what you decide to do, figure out what power demands you are even thinking about before you purchase one.  Most people underestimate power demands and purchase a genny too small to handle it.  And, if you are even considering the thought of the genny for stand-by power at home when the power goes out for a couple of days, you might consider a much more quieter generator (and much more expensive).  If you live in a residential neighborhood, your neighbors will be much more tolerable of the noise.  If that is the case, it is a big bite out of the wallet.  But if you take care of it with proper maintenance and care, it will last you for years.

Just some thoughts.
 

ironrat

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Loma Rica, Ca
If your really set to run your trucks engine I would look at a generator mounted to your engine. I have a 6,000 watt one mounted in my truck and it works fine for it's use, The unit is no bigger than an air conditioning compressor.
 

John From Detroit

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Can you use your truck as a power source: YES

As for "The average TT Inverter" No such beast,, Installed inverters range from a low of aroudn 300 watts up to around 3,000 watts, Mine (motor home after-market) is 2,000 watts, with several smaller ones in the basement.

PROBLEM. if you are running jumper cables from the truck to the trailer, and using an inverter in the trailer, odds are you will not be happy, voltage loss in that long a run will shut down the inverter.. You seriously need batteries in teh trailer for a large inverter,  At least one pair of GC-2 Golf car batteries per kilowatt of inverter is recommended, half that will work.

Alternative: Put something like an X-Power 1,000 (I have a spare if you wish) in the truck.. That will fly.
 

Toaster

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Ah, I guess a small starter generator would be the best way to go for electrical. Thanks
 

TexasToast

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South Texas Oilfields
Howdy, I'm new to the forums. Working down here in South texas in the oilfields I had need of mobile power out in the field and I'll tell ya what I did. I bought two 8D heavy equipment batteries. Each one had 1450 amps and placed them in the bed of my truck. We ran a heavy gauge power line from the alternator with a box on it my buddy installed. He said it allows the generator to charge the batteries but doesn't allow them to draw juice from the truck battery. Then we grounded them to the frame. I don't know what two 1450 amp 12 volt batteries will give you wattage wise. but they powered my 15 amp angle grinder through a 3500 watt inverter all day and never died without the truck running
 

Seajay

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Personally, I would vote for the generator as a solution to your problem.  Using your truck for the primary generation of power to the inverter is going to get expensave.  The truck will burn probably three times the amount of fuel to produce the same amount of power as the generator and you can carry the generator around like a suit case if necessary, according to the size you might buy. 
I have had two ''A'' class campers and one ''C'' class camper and all had a built in generator and we used them a lot. 
My primary rule when I look at a coach to buy is that it have a Generator and a Spare tire because you never know when you might need either one of them.
Remember, this is just the rules I live by and I am probably wrong so I advise you to  not to  take my advise but I will tell you this ... If you are ever stuck somewhere and need a Spare Tire (and mine will fit) or a Generator (and you got the cord to plug in)  I will be glad to help you, or anyone, out of your problem.....

God bless our troops and bring them home safe and soon .....
 

TexasToast

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Yeah the 8D batteries will run you about $220 a piece. You might be able to do it with one, using a power tool that uses less amps. A 15 amp angle grinder is a professional grade power tool, It's what welders use to grind down there welds.
I had two batteries because they came off a junked out city bus in really good shape. I payed 60 dollars for the pair. But I used them without the truck running. To be honest I think what I would do is purchase a small generator(All Power America 2-Stroke Portable Generator ? 1000 Surge Watts, 850 Rated Watts $150.00) that uses little gas. Hook it up to a couple of cheap car batteries through a 40 amp battery charger. then run an inverter. Power tools are most often used in short bursts. if you hook them up directly to the generator, it has to be running for them to work. Off an inverter, you just fire up the generator when the batteries get low. Might sound like a lot of trouble but it'd be the cheapest route in the long run.
 

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