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dick white
Premium
join:2000-03-24
Annandale, VA
reply to nunya

Re: Using a hybrid car for power in case of blackout

said by nunya:

{...} I buy them because I don't want to listen to a generator run all day. {...}

When the Prius was still a new novelty, there were rumors that Toyota was going to port the hybrid system to one of their pickup trucks, with some built-in 120V plugs, aiming at the contractor market for running power tools at the job site. Like many rumors, it never came to be.


PSWired

join:2006-03-26
Annapolis, MD

The GM hybrid pickups have (had?) this feature.



Jack_in_VA
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North, VA
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4 edits
reply to dick white

said by dick white:

said by Jack_in_VA:

I think you have a big misunderstanding of how this works. If the vehicle is not being driven then no power is taken from the traction batteries. The traction batteries consists of 346 Li-ion 3.6 volt cells connected in a series-parallel circuit.

Prius Electrical

The batteries are high voltage, the generator is 3-phase high voltage used to charge the batteries is high voltage.

They cannot be used to power anything else.

Click on the Prius Electrical link above for a description of the components and their functions.

Excuse me, Jack, I have owned both a 2002 Prius and a 2009 Camry hybrid. Years ago I outfitted the Prius (and used it) in exactly the manner described. Your understanding of the motor-generators and the high voltage battery pack is incomplete. The traction battery is used to recharge the 12V battery as needed. The 12V battery operates only the controls and accessories. Hence, if the 12V battery is discharged (usually by leaving a door slightly ajar with the interior light on overnight, don't ask how I know this...) before starting, the car will not start only because the computer controls cannot be booted. But once the car is running and all control systems are operational, the 12V battery continues to power the radio and lights. Thus, it needs a steady source for recharging, which it gets through a step-down from the traction battery, regardless of what else the traction battery might be doing at any given moment.

The motor-generators (there are two of them) are geared together with the output shaft of the gas engine in a unique power-split device (not a conventional transmission) that allows all three to operate independently, or in tandem, or rotate in contrary motion under certain circumstances. The larger of the two motor-generators is the actual drive source for the wheels. Because an electric motor can be spun in either direction by changing the polarity of the current, it can drive the car forward or in reverse. During regenerative braking or downhill drifting, it changes mode to a generator to recharge the traction battery. If more power is needed to drive the car than is available in the traction battery pack or if the power demand exceeds the output capacity of the primary motor-generator, the gas engine will start and some of the engine power will be split off to turn the second motor generator while some of the engine power is directed to assist the primary motor, if needed. If the primary motor-generator has sufficient power for the present driving needs but there is insufficient voltage in the traction battery, the entire gas engine power output will spin the second motor-generator in generator mode to recharge the traction battery. This is the "emergency" setup we are discussing. There is no motive demand on the primary motor-generator as the car is stationary, in park, but the traction battery is discharging because the 12V system is powering stuff in the house as well as the accessory system of the car. The computer doesn't know that, all it knows is that the 12V battery is constantly running down. So it bleeds some current over from the traction battery. At the point when the traction battery is discharged below its setpoint, the gas engine will start, and drive the secondary motor-generator until the traction battery is recharged.

(And finally, in the interest of completeness in describing the multiple configurations of power flow through the power-split "transmission", if there is a full charge in the battery pack and there is an extreme demand for motive power, e.g., acceleration for passing or a jackrabbit start, all three sources, the gas engine and both motor-generators will go into power mode. But this will last for only a short while until the traction battery is drawn down below its setpoint, and then the secondary motor-generator will shift back to generator mode drawing on the gas engine for its power source, and the car's acceleration will quickly fade. At higher speeds, the gas engine must be spinning to offset the RPMs of the secondary motor-generator below its maximum rating so it doesn't explode. This can result in a phantom mode at higher speeds with low motive power demand, such as coasting down a hill, where the gas engine will be spinning but with the fuel injectors off and the valves open. It really is an interesting technical/automotive tour-de-force.)

cheers
dw

All of that doesn't address the fact if you hook an invertor to the 12v battery it is no different than hooking it up to any vehicle. Like nuya said you just start the vehicle and charge the battery(s) as they run down. In the case of the prius the main battery provides the source but at a rate the 12v battery can safely accept.

You can't access the main battery except for it to recharge the 12v battery which limits the amount of power available to what the 12v battery and inverter can safely provide. A 12v battery is not an infinite source of power regardless of the ability to charge it.

It is an inefficient awkward effort at best and a small emergency generator would be a much better choice unless you just want to charge your cell phones and maybe run a laptop and small light. Leave your headlights on with the engine off and you'll get an idea of how much power is available in a standard 12v battery and how long it will provide that power.

All of the manufacturers are working on making the main battery accessible for emergency use providing power for homes in blackouts. They are not available here yet.

»usnews.nbcnews.com/_news/2012/11···use?lite

quote:
Sakala says he first read about the Prius' use as a power source years ago on the internet.

After the storm, and the resulting power outage, he thought he'd give it a try. He ended up powering a few lights, his TV, laptop and modem with a 100 watt power inverter and a few heavy-duty extension cords he purchased at Home Depot. He later moved to a 300 watt inverter, which let him power more lights.
It had to be a very small tv to power it on a 100 watt inverter "along with a few lights". Add it up 100 watts is 100 watts.

Google "Using hybrid vehicles for power in emergencies"

Bob4
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said by Jack_in_VA:

It is an inefficient awkward effort at best and a small emergency generator would be a much better choice

Which is exactly what Mr. White said.

said by Jack_in_VA:

It had to be a very small tv to power it on a 100 watt inverter "along with a few lights". Add it up 100 watts is 100 watts.

My 40" LED TV uses about 25 Watts.


fifty nine

join:2002-09-25
Sussex, NJ
kudos:2

Maybe jack is thinking of his 500 watt incandescent power hogs when he thinks of "a few lights". Using led or cfl I can run about 8 lights on 100w.



leibold
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reply to haroldo

I'm surprised by all the comments here insisting that the high-voltage traction batteries cannot be used to provide emergency power ?
PRIUPS is one site that has documented how to do it and there are a few others that did their own variation thereof. It is not trivial and I'm not suggesting everybody should do this (needless to say, electricity can kill and there is a reason for all the warning labels on the high voltage system in the car) but it is certainly possible.

A 2005-2009 Toyota Prius is capable of providing more then 5kW at 220V DC (not AC!) at the traction battery. That is similar to the amount of power that you get from an emergency generator (3 to 7kW for many portables).

In some cases (electronics with a 120V-240V switchmode power supply) you may be able to directly power AC devices with this 220V DC voltage. For anything else requiring 120V AC you will need an inverter. PRIUPS and others had success with using an industrial UPS that uses high battery voltage (most consumer UPS use 12V or 24V inverters).
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Jack_in_VA
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reply to Bob4

said by Bob4:

said by Jack_in_VA:

It is an inefficient awkward effort at best and a small emergency generator would be a much better choice

quote:
Which is exactly what Mr. White said.
Not quite he still is presenting the prius as a emergency source. Googling the issue it is apparent it could be a future source of power but it's not ready for prime time yet.

said by Jack_in_VA:

It had to be a very small tv to power it on a 100 watt inverter "along with a few lights". Add it up 100 watts is 100 watts.

quote:
My 40" LED TV uses about 25 Watts.
My Sony 46" is listed at 240 watts, not including the Directv DVR and Sony Surround Sound System.


Jack_in_VA
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3 edits
reply to leibold

said by leibold:

I'm surprised by all the comments here insisting that the high-voltage traction batteries cannot be used to provide emergency power ?
PRIUPS is one site that has documented how to do it and there are a few others that did their own variation thereof. It is not trivial and I'm not suggesting everybody should do this (needless to say, electricity can kill and there is a reason for all the warning labels on the high voltage system in the car) but it is certainly possible.

A 2005-2009 Toyota Prius is capable of providing more then 5kW at 220V DC (not AC!) at the traction battery. That is similar to the amount of power that you get from an emergency generator (3 to 7kW for many portables).

In some cases (electronics with a 120V-240V switchmode power supply) you may be able to directly power AC devices with this 220V DC voltage. For anything else requiring 120V AC you will need an inverter. PRIUPS and others had success with using an industrial UPS that uses high battery voltage (most consumer UPS use 12V or 24V inverters).

The Prius voltage is higher than 220 and are you suggesting that someone dismantle the vehicle to gain access to the batteries themselves? That would void any warranties instantly to subject the vehicle (batteries) for this use.

Toyota, Nissan and others are working on this especially for use in Japan. It's not here yet. Just because something is technically possible doesn't mean it is realistic to do. As your link points out there are many considerations that need addressing before this becomes feasible.

Running an Inverter off a Prius for Backup Power

How I added an inverter to my 2005 Prius

A lot of effort for less than 1000 watts


Cho Baka
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reply to Jack_in_VA

The Prius or any other hybrids with this type of hybrid system are actually far more efficient than a conventional vehicle when used in this manner.

Reasons:
1. The engine is used at a far more efficient loading than conventional vehicles would be when operating to charge the HV battery. (gasoline engines are extremely inefficient at idle)

2. The engine need not idle unnecessarily.

3. The vehicle and all systems are designed to operate in this way. There is less risk of letting the 12 V battery discharge to a harmful level as there would be in a conventional vehicle.

4. The vehicle emits far fewer pollutants than any conventional portable generator.
--
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Jack_in_VA
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1 edit

How I added an inverter to my 2005 Prius

It's a lot of equipment and work for the less than 1000 watts. The average person would not have the ability to do this safely.



Cho Baka
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reply to Jack_in_VA

said by Jack_in_VA:

I think you have a big misunderstanding of how this works. If the vehicle is not being driven then no power is taken from the traction batteries. The traction batteries consists of 346 Li-ion 3.6 volt cells connected in a series-parallel circuit.

Prius Electrical

The batteries are high voltage, the generator is 3-phase high voltage used to charge the batteries is high voltage.

They cannot be used to power anything else.

Click on the Prius Electrical link above for a description of the components and their functions.

Jack, it is clear that you don't have a clue how the vehicle operates, and that you are cherry-picking and obscuring sources you are using to "prove" your "knowledge".

The source you "cited" above is not applicable to any of the Prius or Camry HV discussed in the thread. It also does not support your contention in the first sentence.

The source you "cited" is the emergency response guide from the Prius PHV. The HV battery in this vehicle is completely different from Conventional Prius or Camry HV.

Dick White has already addressed this.

You are in left field without a glove on this one...
--
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Jack_in_VA
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1 edit

How I added an inverter to my 2005 Prius.

This person knows what he's doing. This is a conventional 2005 Toyota vehicle with the conventional HV battery used in 2005.

In Japan the average kW demand for a house is 10kW so a 20kW hybrid would power it for 2 days. Not bad. They just have to get the system designed and in production.


dick white
Premium
join:2000-03-24
Annandale, VA
reply to haroldo

Ok, everybody back to your cages.

The OP asked about using a Camry hybrid for emergency power, perhaps after seeing some recent news reports of such after Superstorm Sandy. It's an interesting question, worth discussing. Yes it can be done, but as some early posts indicated, it would be easier and cost about the same to just get a small generator.

Then the discussion veered off into how much battery capacity is available in a hybrid Camry. A Prius has essentially the same hybrid system, and I actually did this with my '02 Prius back in 2004 or so. I did it pretty much the same as the article about the 2005 Prius (Jack, FYI your link is whacked -it is a video of the Oak Ridge Boys singing about G.I. Joe, nothing about a Prius...), except that I used a different connector (3-prong twist-loc), his plywood rack was neater than my plywood slab, and I used a cheaper modified sine wave inverter instead of a full sine wave model, and I did it several years before he did (and there are others out there who were doing it also at the same time, it was not my original idea and I claim no intellectual property for it). The reason I did it was because back then, there were no cheap small genies for sale at every big box hardware store or online. However, as I pointed out, despite the apparent availability of humongous amounts of voltage under the back seat and generating capacity under the hood, not much is available for external use through an inverter. A Prius/Camry hybrid can provide no more external emergency power than a conventional car with an inverter clamped to its battery, and I explained why. The only advantage the hybrid system has over a conventional car parked in front of your house with an extension cord hanging out of the grill is that the Toyota hybrid can start and stop its engine automagicallly as needed to keep the 12V battery, which is the input source for the inverter, at full charge, and I explained how that happens through the genius of their unique power-split "transmission" and sophisticated computerized controls. Even nunya has to go out to his truck and start/stop it manually every few hours. And now that cheap small genies are readily procured, why bother.

As for accessing the full capacity of the hybrid's generating system by tapping directly into the HV battery pack - nobody is disputing that it technically can be done, just that the ordinary JoeSchmoe shouldn't even think about it.

dw


Bob4
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reply to leibold

said by leibold:

A 2005-2009 Toyota Prius is capable of providing more then 5kW at 220V DC (not AC!) at the traction battery.

OK, but how much continuous power can the Prius engine+generator provide? If the engine can't meet the demand, you're fighting a losing battle and the batteries will eventually die.


Jack_in_VA
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North, VA
kudos:1
reply to dick white

Dick sorry about the link. I evidently am on too many sites today.

I agree entirely with your post. Perhaps the technology will be available soon so that it's more or less a "plug in".

Meanwhile a generator is the best option IMO.



fifty nine

join:2002-09-25
Sussex, NJ
kudos:2
reply to Jack_in_VA

said by Jack_in_VA:

My Sony 46" is listed at 240 watts, not including the Directv DVR and Sony Surround Sound System.

The newer LED HDTVs are much more energy efficient than older CCFL backlit displays. My home theater with the Sony 52" can burn up to 1kw when everything is running. The newer LED in the kids room burns less than 50w.


leibold
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reply to Jack_in_VA

said by Jack_in_VA:

It's a lot of equipment and work for the less than 1000 watts.

said by How I added an inverter to my 2005 Prius :

I've read about other Prius owners (www.priups.com) connecting a sophisticated inverter to the 201.6 VDC (nominal) traction batteries and getting a significant amount of power from their car.

The very first paragraph of the document states clearly that other Prius owners have been able to get a significant amount of power by connecting to the high voltage traction battery. Despite knowing this, the writer of that document decides to use the 12V subsystem instead. He did that to avoid warranty issues and that is perfectly understandable but unlike most cars the 12V system in the Prius is very weak and cannot support a powerful inverter with its high current draw.
The high voltage system is a completely different story. The Prius has two motor/generators. The larger one (50kW) cannot be used while the car is stationary but the smaller one (20kW) can and as long as the car is "Ready" it will automatically start and and stop the engine to keep the high voltage battery charged (using the 20kW generator).
That is plenty of power even when taking distribution (long power cords) and conversion (poor inverter efficiency) losses into account.

said by Jack_in_VA:

The average person would not have the ability to do this safely.

Agreed.
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dick white
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join:2000-03-24
Annandale, VA
reply to Jack_in_VA

Jack, the first iteration of your link in an earlier post did work correctly, only the second iteration just above here didn't. No harm, no foul. There are already some cars in the market now with a low-rated 120V plug in the console for powering small electronics, etc., just plug it in like inside the house. It can be done, but my personal opinion is that it probably won't be done on any large scale. Plugging in your laptop while sitting in the car is an entirely different beast than running household appliances. The moment you depart from a simple plug for a laptop and move toward larger-scale external applications, you enter a zone where significant judgement is required by the end user. Whenever such significant judgement is required, the manufacturers are going to be leery of the liabilities. If the ordinary bozo has a car with a plug under the hood labeled "In case of emergency, plug in your refrigerator here," what is to stop him/her from adding the toaster and the coffee pot and whatever else can be strung off the extension cord(s)? When the car electrical system blows out or the house burns down, who takes the blame? Car manufacturers just aren't going to put themselves in the middle of that. JMO, however nice the idea might be.


Bob4
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reply to Jack_in_VA

said by Jack_in_VA:

In Japan the average kW demand for a house is 10kW so a 20kW hybrid would power it for 2 days.

I think you're confusing kW and kWhr.


Jack_in_VA
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said by Bob4:

said by Jack_in_VA:

In Japan the average kW demand for a house is 10kW so a 20kW hybrid would power it for 2 days.

I think you're confusing kW and kWhr.

Thank you so much for pointing that out to me. I will try not to make mistakes in the future.


Jack_in_VA
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reply to dick white

said by dick white:

Jack, the first iteration of your link in an earlier post did work correctly, only the second iteration just above here didn't. No harm, no foul. There are already some cars in the market now with a low-rated 120V plug in the console for powering small electronics, etc., just plug it in like inside the house. It can be done, but my personal opinion is that it probably won't be done on any large scale. Plugging in your laptop while sitting in the car is an entirely different beast than running household appliances. The moment you depart from a simple plug for a laptop and move toward larger-scale external applications, you enter a zone where significant judgement is required by the end user. Whenever such significant judgement is required, the manufacturers are going to be leery of the liabilities. If the ordinary bozo has a car with a plug under the hood labeled "In case of emergency, plug in your refrigerator here," what is to stop him/her from adding the toaster and the coffee pot and whatever else can be strung off the extension cord(s)? When the car electrical system blows out or the house burns down, who takes the blame? Car manufacturers just aren't going to put themselves in the middle of that. JMO, however nice the idea might be.

Dick from what I saw on the various sites that's a big part of the problem for the manufacturers. They are working on it but aren't there yet. According the the one site they stated that in Japan the average electrical demand was 10 kWh and since the batteries were 20 kWh that would power the house for at least 2 days. That is significant. The article didn't state how long it would take the engine/generator to recharge the battery.

The whole concept unless they can just provide a simple plug that's protected it will not be for the average person.

dick white
Premium
join:2000-03-24
Annandale, VA

said by Jack_in_VA:

According the the one site they stated that in Japan the average electrical demand was 10 kWh and since the batteries were 20 kWh that would power the house for at least 2 days. That is significant. The article didn't state how long it would take the engine/generator to recharge the battery.

Well, there you have the USA problem in a nutshell. Just grabbed a recent electric bill from the drawer, I'm using ~20 kWh daily, and I live by myself in a small house with modest demands. In Japan, living spaces are much smaller and less stuff consuming power. Even so, I'd have to go back over the math before I'll believe there is enough juice sitting under the back seat of the Prius/Camry to run my whole house all day, presuming that we had an easy, convenient, and safe way to plug the house into it.

I once toured a "solar" house that the owner was touting as grid-tied net-zero-metered, meaning he had enough PV panels on the roof to, on average, generate more power back into the grid during the day than he took out at night. Nothing unusual there. What was unusual was that he had off-the-grid backup capability with a basement wall full of lead-acid batteries that could, if the grid went down, keep the house running forever. However, he said that during an extended outage, he had to carefully manage the high demand appliances (stove/oven, HVAC) to keep from discharging the batteries at night or on cloudy/short winter days. No way that the batteries under the back seat of my Prius/Camry could match his basement wall.


Jack_in_VA
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I have the same problem. I average over 1000 kWh/mo and I checked once on Solar Cells and it would have been $33k for enough cells for 1/2 of my demand. We only pay about 10.5 cents per kW including all taxes and fees, here so it's hard to justify some of these things.

I'm very familiar with inverters and battery backups. We had them all over the plant on our switchgear to operate the trips in case of power failures. Each one had a universal motor with a gear head. The batteries were a major problem as they required constant maintenance.

Also the power plant had the same set up but in addition had a very large 240 volt inverter that floated on the line to provide power to the instrumentation to be able to shut the high pressure boilers (1500 psi) down without them blowing up and shut the turbines down without damage until the emergency generators kicked in.

I've got a Honda EB5000X non-inverter industrial generator I've used since 1997 with no issues. I power tv's, computers, modems, and everything else except my heat-pump. I've used the heck out of it given I'm in the middle of no-where so we have a bunch of long outages.


Bob4
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reply to dick white

said by leibold:

The high voltage system is a completely different story. The Prius has two motor/generators. The larger one (50kW) cannot be used while the car is stationary but the smaller one (20kW) can and as long as the car is "Ready" it will automatically start and and stop the engine to keep the high voltage battery charged (using the 20kW generator).

said by dick white:

I'd have to go back over the math before I'll believe there is enough juice sitting under the back seat of the Prius/Camry to run my whole house all day,

If leibold is correct about the 20kW generator in the Prius, it should be no problem running an entire house. That's 90 amps @ 220 Volts.

And 20 kW is only 27 horsepower, so the engine should have no trouble keeping up.


Cho Baka
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reply to dick white

Your 20 kWh daily usage presents no challenge whatsoever.

What would be more of a challenge are you peak loads, measured in kW.

The second gen Prius (2004-2009) has a 50 kW generator (MG1), and could easily handle anything a residence could throw at it.

What is necessary is an inverter to handle this. A vehicle could easily be built with an integral inverter (as opposed to a DC-DC converter + 12 V to 120V inverter) to access a good chunk of this power, but finding enough takers to make it a financially viable option on a hybrid is likely where the holdup lies.

Consider that all Toyota configuration Hybrids have at least 2 inverters + a boost inverter as things stand - these are used for control/operation of MG2 and MG1.

Here is a link that shows a system (previously alluded to) being developed for Japan based on the plug-in version of the Prius:
»www.4wheelsnews.com/toyota-prius···nerator/
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M A R S
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Long Island
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reply to haroldo

Slightly off topic. I used my 1993 Volvo 240 with a 750 watt inverter for 8 days i had no power during the aftermath of the Sandy. I ran my furnace a few lamps with CLF's and a LCD TV. I would let the car idle for 3-5 hrs at a time 2 times a day. Oil pressure, volts and temp were spot on and this used a small amount of a gas a day. This set up saved me. People were amazed i could do this but it was just common sense to me. I had heat and light.

I Should also add, i did this because i let my generator to a family with an infant and there was no way you could get one in the days after the storm. We here on Long Island got hit very hard. I was lucky my house made it with only a few trees that fell around it. The Volvo on the 750 watt inverter i had truly saved our ass.


Bob4
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New Jersey

How many Watts can a typical automobile alternator provide?



leibold
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said by Bob4:

How many Watts can a typical automobile alternator provide?

Car alternators are usually spec'd by current instead of power and 50A to 100A seems to be a common range with high-power after-market car alternators going up to 200A. At 15V charging voltage that would be anywhere from 750W to 3kW.
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dosdoxies
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Wallingford, PA
reply to haroldo

If I recall correctly, back in the early to mid 70's Ford had an option on the T-Bird called the Sierracin option in where the alternator had a 120V output for the grid style defroster in the windshield. Only think I ever ran across one in my 40 years as a mechanic.
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
reply to haroldo

Here's an interesting product:
»www.aurasystems.com/pages/prod_intro.html