SkoorbMax

With the power out recently due to Ivan, I was looking at those DC -> AC invertors (or is that convertor? ). I know that diesels can idle forever, but is there much of a problem with a gas one revving for a long while? Clearly it's receiving some wear, but would be it be negligible - somewhat in line with the very slight amount of gas actually running through the car?

While I'm at it, I see a DC -> AC that is 750 W continuous, with 1500 W peak. Would our alternators be able to handle that (with the stereo turned off and lights off), and if not, what's the most powerful adapter you could really put in a standard max?

unsprung

I don't believe you'll run into problems leaving the engine idling for a long period of time, but if you plan on using a 750W invertor that will most likely be wired straight from the batter, be aware that the alternator won't be charging up the battery like it is when you're driving usually. If you plan on using the invertor for long periods of time, might want to look into a deep cycle battery like a Optima Yellow.

Mr. Peabody

DC -> AC is properly described as an inverter. For a LOT less $ than having to replace the Maxima alternator you could go to any marine outlet store and purchase several large deep discharge marine bateries that you could hook up your inverter to & run the frige and a small lamp or two for quite a while.

Peabody

Broaner

iTrader: (10)

By the time you get an answer to this your gonna have your power back. I currently run a 200W inverter with my headlights on and system on with no problems.

Ant96GLE

iTrader: (4)

GOod question, I'd like to know this too. Some people say its not good since theres no load on the engine and you dont get as much oil up on the valves as you should. Thats what I've read here on the org before. How true is it, I dont know.

Mr. Peabody

The other issue to consider is overheating the engine. If the car is going to be sitting for "hours" just idleing there is very little air flow other than what the electric fan produces.

On the other side of the coin police often let their cars idle for hours with lights flashing at accident sceans but they probably have slightly more heavy duty systems.

Peabody

Ant96GLE

iTrader: (4)

POlice Interceptor cars have better cooling systems not for just coolant but for engine oil, power steering oil and the such...

CandiMan

iTrader: (1)

To answer your question I don't think you'll have a problem idling your car for a long time. At idle your engine produces it's least amount of power so it generates its least amount of heat. The radiator fans can provide enough air flow to properly cool the motor at idle.

My question to you is, what exactly are you trying to power up with your inverter. Is 500w continuous enough power to supply your avg household equipments?

I hear you when it comes to not having electricity for an extended period of time. A lot of folks in Palm Beach Co. Florida lost power for a couple weeks after Huricane Francess.

MIKE

Muravchik

I'm not sure about the dangers of idling for a long time, but I have a 400W inverter and can play playstrion for hours with the car off with my Optima yellow top. The thing you need to worry about if you plan on running the inverter for a very long time with car idling is that the alternator won't put out much power at idle. I think our alternators put out good amperage at around 2500-3000 rpm. Correct me if i'm wrong...

Dave Holmes

On the issue of overheating, if you're worried about heat buildup while idling for extended periods, open the hood. Makes a drastic change.

Police Interceptors do have an oil cooler to help them out. However, I don't think their overall cooling system is as efficient as a Maxima's. I've overheated several Interceptors while idling with high electrical loads in Louisiana's summers at traffic accidents/shootings/etc when I didn't have time to open the hood. When I had the time to open the hood, I never overheated one, even with 4-6 hours of idling. I ran a '96 Maxima for over a month in the Louisiana summer with the passenger side electric fan unplugged because it was bad. Only effect it had was the AC got warm at stoplights and other idling situations. And unplugging the fan was a Nissan tech's idea, who said it would cause no damage. He was right.

As for idling my personal car for extended periods, I try to avoid it. I think the main issue is oil pressure remains relatively low. There may be other valid reasons, but I just avoid it. The post about several marine batteries to power your stuff is a good idea.

Dave

spirilis

iTrader: (2)

I think it probably runs a little rich at idle, so you'd carbon up the cylinders. Better run some SeaFoam through it afterwards

SkoorbMax

Thanks for the responses

bert

I have also heard that long periods of idling may cause poor lubrication due to the fact that the oil pump is designed to primarity operate at higher RPM.

Matt93SE

iTrader: (44)

oiling and cooling issues aside, you need to look at the electrical load on the car.

a 750W invertor- when putting out a true 750W, will suck somewhere around 80A of current from the car..

those things are usually never more than about 60% efficient, but let's say it's 80% efficient just to be conservative.
750 / 0.8 = 937.5W actually drawn from the car's electrical system.
937.5W/ 12V = 78A. and again, that's assuming the invertor is 80% efficient.
if it's 60% efficient, then the current draw will be 105A.
But that's also at 750W continuous output. are you really going to be using all 750W all the time?


at idle, the alternator will barely be able drive the invertor at 80A, but will likely overheat and die an early death if you run the invertor at full power for a long time like you're talking about.. 10-15 minutes is one thing, but hours on end is another thing. the alternator just isn't designed for it.
now if you had an aftermarket 300A alternator and kept the idle on the car around 3000rpm, then it would have no problem feeding that invertor all day. but you'd eat gas like you wouldn't believe.