Max Electrical Power Output Of A Car

I bite! Where from in which car, what for?

an average diesel/gasoline car

It depends . Depend on type of power source you are using , the batteries , and other factors . Here is a site which tells you about some of the most powerful electric cars made. Tesla S is just the tip of the iceberg . But Tesla S is a good electric car.

https://www.mnn.com/green-tech/transportation/blogs/4-insanely-powerful-and-expensive-electric-cars

It also depends on which sense are you judging the car. By its speed or acceleration or what ?

not an electric car, a gasoline one

Who says its an electric car?

the power needs to be drawn for about 10-20 minutes. it's one high current circuit. No modifications are made to the vehicle electrically. i'm expecting at least 100W of power output, while the headlights and the infotainment systems are running. possible?

Let's just imagine that the battery is 60AH (reasonably typical). If you draw 60A for 15 minutes the battery would still remain 75% charged. 60A x 12V = 720W. The wire (and fuse) will need to be sized for the amp draw you need.

OP hasn't been 100% clear, but it seems more than likely he wants his 100W with the engine running, not draining the battery.

It is determined by the rating of the protective devices, usually fuses, in the wiring. The vehicle's wiring diagram and user manual can not be seen from here.

First of all do a google search for the specification of the alternator for the car your going to use. So, search for say

"Chevrolet cavalier replacement alternator specification"

I ended up with this spec:-

http://www.autozone.com/batteries-starting-and-charging/alternator/duralast-alternator/352089_938138_0

It's probably reasonable to assume that you could take 30% (~360 W) of this power over a long period or almost 100% over a very short period.

Of course you need to make sure that you have the necessary wiring and fuses in place.

This is of course purely hypothetical as your chances of finding a 2000 Chevy cavalier which will start are vanishingly small.

Hello,

In Australia we have a 7 pin trailer socket that runs the standard trailer accessories and then there is a 12 pin option that includes a system to charge accessory batteries and such while travelling. The battery circuit is protected by a 15 Amp fuse, so 100W is no problem for a standard car.

There are multiple cars that have additional headlamps (spotlights) for remote driving with light capability over 100W for those lights only. again, should not be a problem.

Holy crap!

Technically they needed the fictional value of 1.21 Jigawatts as stated in the films by both future (present) Doc, past Doc and future (present) Marty.

"J" or "G"... it's all in the pronunciation..... Jim went to the gym.

...but it is not pronounced jugawatts

It is Gigawatts, like you got a new gig, get it? Not jig, as in jigger's up drunks!

Giggity!

Quoting Quagmire from Family Guy.

OR did you mean, Jiggly?

The American pronunciation in the "Back to the Future" movies where this came up were very clear in my mind and not open to misinterpretation in my opinion. "Jig" and "Gig" are very different sounds and it was clearly "Jigawatts" both actors were saying.

What we have here is a failure to "respect my authoritah!" Gigawatts is spelled with a "G" for a reason. Now get yur butt to units detention facility!

Jack, read this. Also check out Merriam Webster's pronunciation.

According to Merriam-Webster's 11th Collegiate, you are correct.

I don't recall that, either, but I wonder what was said in the movie "Back to the Future".

That's not a typo. Jiggawatts is similar to Bazillionwatts. Gigawatts is an actual unit.

What the hell is a Jigawatt? Is that related to Dan Fielding on Night Court?

GREAT SCOTT!! Does no one remember the American movie classics from the 80's?

One could always go back in time and sort all of it out.

And you and I both hate grilling 3rd degree burn lines into the palms of our hands when wires melt. I just hate when that happens! LOL!

It is indeed nasty to have very hot short circuited wire in hand with molten sleeve which sticks to skin. We often save our hands and let the battery go to hell, and it sure does.

I would rather not have that entire event take place to begin with, and thank you so much for sharing that "lively" experience with us.

Goshee that has to hurt. It is as though someone picked up a branding iron out of the fire by the wrong end!

Assuming you may place the drive wheels of said "running" car on a dynamometer, I would say it is very nearly the sticker horsepower rating.

Otherwise, you are limited by the amount of power you can pull off the alternator.

Look into automotive sound systems. They typically use around 100W and there's a lot of info on how they do that.

I just googled "max amperage alternator" and found a 370 Amp E Series Alternator with Black Finish for Select 1994 - 2003 GM 2.2L SOHC Engine Vehicles, $699. This is a apparently a bolt on accessory. Of course, you might need some hefty cables from the alternator.

Joel

Forget cabling, that bad puppy needs silver plated bus bars!

There are two limiting factors: Battery capacity and alternator capacity. Everything else can be compensated for. This is a common question when adding a winch to a vehicle/trailer. A larger battery can supply a larger amount of power until it's discharged; how long it takes to recharge is dependent on the alternator. Sometimes a second battery is added to ensure that you still have starting power from the main battery, so that you don't get yourself stranded. You could also make a trailer with 12vdc power tools for a mobile shop, with its own battery that's recharged from the tow vehicle via a large wire from the alternator thru the trailer connector to supply a large amount of "recharge current" to the trailer's battery. The point is that the battery can act as a buffer for large loads when the alternator can not supply it in real time. How fast the recovery time is from that deficit, depends on how fast you can recharge the battery.

Please define "everything else." That appears to be a fairly wide class of objects.

Well, you got me there. I was referring to collateral items like cables, fuses, connectors,etc. But, for for that matter, I suppose that even the battery(s) and alternator can be upgraded also, as long as space/mounting-brackets, etc, can support it.

Are you talking about from the piddly little alternator on the engine? OR, are you thinking about putting the car on a set of rollers, which are attached to a large generator, and using the energy, that the spinning tires could produce from that set up?

If he only wants 100W, even in addition to usual loads, the piddly little alternator on the engine would be fine.

Before alternators came in output of a standard dynamo was 22A (in UK, can't speak for USA). So even a small alternator isn't that piddly by comparison.

If you check out various US cars you will find a series production socket for 110v supply which is far higher than a normal 12v system allows, using a 12v DC Invertor.

Also there are 12v power winches fitted to SUV's that draw 500+ Amps at full load.

In addition there are certain vehicles ( Land Rover for example) that can run hydraulic power take-offs from the gearbox which is yet another form of power. These hydraulic systems can be used to run Generators, one was 240V 5KvA 21 Amp.

Some also used a belt driven system from the motor.

Current new vehicle architecture is using 48v systems to power stop-start, Aircon, Power Steering etc.

Is this a question about dynamometers?

Should have been, IMHO! Alternator smallternator, let's see some real power here.

That is what I asked in post #30.

#18

Re: Max Electrical Power Output Of A Car

Same thing I said in post #18.

If you run a lead from the battery to the outside world: Power drawn from the battery, say 40A, assuming 40AH battery and you are going to run for about one hour. If you run longer, reduce current drawn from battery. The lead from battery to alternator is rated at about 100A continuous, determined by its diameter/circumference (not its cross-sectional area), to get rid of heat. So alternator/100A + battery </= 140A for one hour. =100A max all day.

If you run a lead from the alternator to the outside world, the limit is say 40A from battery plus alternator rating, for one hour. Alternator rating only if all day.

If you run from elsewhere in the wiring loom, the limit is set by fuses in circuit and the conductors between take-off point and battery/alternator.

I have not allowed for ignition requirements. I assume you are not moving, have vehicle doors closed, you are in daylight, nothing switched on other than ignition, no other external connections, and you don't smoke (don't light up using the electrical system).

Diesel engines require very little power when running, you can safely ignore it.

My car has a cooling water heating system, that warms the water when the engine is cold, but we only use it in winter time.

But due to that, it has a 12 volt nominal, 120 amp alternator from the manufacturer.

Most of this would be available, without using the battery at all if need be. Your 100A cable would be too thin.....In such cases I always use starter cable, its usually good for 400 amps or so, and is reasonably priced.....of course a proper fuse would also be a good idea as well for safety.....

Also, a long time ago, someone here mentioned "after market" alternators, that can be fitted to cars/trucks, giving quite large current outputs of either 12 or 24 volts.....but I cannot remember who or where, sorry! But more than my car's alternator, that I do remember....

Also, someone added an alternator quite cleverly to a boat's engine , fairly recently on CR4.....not that much different.

Of course the OP has been exceedingly sparing with details, so he has really left us all in the dark and guessing.......

I totally agree with you, Andi. Diesel engines need the power to start the starter and to sustain very minimal electrical stuff especially those old engines.

That's right, in the good ol' days you didn't need a battery at all, tow start it and away you go. Of course that's road vehicles, small stationary engines and petrol/TVO tractors with magneto ignition and swing start don't have a battery anyway.

You are correct... I do remember those olden day. But now modern diesel engine needs a contious supply of electricity to power its ECU. Technology at its best!

You slightly missed the point to my mind, it was actually mentioned by myself in passing too:-

Yes, it needs power, but it needs only milliamps for itself!!!!

Certainly far less than 1 amp!!! Probably only 500mA or less.....

But lets go with say 5 amps! To include the valve control solenoids and stepper motors (which are only used when needed, not continously!) and the like!

Still unnoticeable in the big scheme of things!! Many cars today have 120 amp or more Alternators........

The "average" power drain, seen over hours, will be quite small!

See here:-

Engine_control_unit

I hope this helps better understanding of the amounts of power needed.

By the way, I have explained for any ECU on cars, but in reality, Diesel engines will use even less total power....few controls, less data.

Oh yeah sorry about that!

I forgot to add in #62 - in the old days of dynamos, before alternators you didn't need a battery to start a petrol engine, just tow it to give engine speed enough to close the cut-out. Then keep revs up and cut-out closed and it will run all day.

Unlikely to work with an alternator as usually not enough residual magnetism in the rotor, and anyway it's risky to run with battery disconnected.

Yes, that is absolutely correct codemaster.