# My car by emergency generator



## Padre (Oct 7, 2011)

My new BOV is a civic hybrid...

I know. If you have finished laughing can we continue? 

I traded in my Tahoe for a Civic. Now I will note that I still have a Ram1500, so don't take away my man card yet.

My thought is that although the civic is essentially a go-cart it goes a whopping 520 miles on less than 15 gallons of gas. I keep about 50 gallons in red cans so on this alone I could cross the US. Or travel to and from the town closest to my BOL 100 times.

AND, from what I understand, hybrids are essentially high efficiency generators with high voltage batteries to make the power loss minimal.

That's what I am posting about...any one have any technical knowledge to offer about considerations I should make in taking power from my hybrid engine? I understand the how is a simple inverter run off the battery posts. Where should I look for specs on how much power the car needs vs how much it is safe to take off?


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## Grimm (Sep 5, 2012)

Padre said:


> My new BOV is a civic hybrid...
> 
> I know. If you have finished laughing can we continue?
> 
> ...


This is an interesting concept I am surprised we don't see more of here in the forum. Now that we have the jeep we have talked about getting a hybrid and I want to know the answer to this too!


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## Geek999 (Jul 9, 2013)

I think the reason you don't see more of this is that folks are more inclined to worry about EMP destroying their ability to go anywhere. Absent an EMP, the OP is absolutely thinking correctly. A small hybrid provides a lot of range on a small amount of fuel and is capable of providing more electrical power than a conventional vehicle.


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## cowboyhermit (Nov 10, 2012)

Great idea, the main problem is that the cars actual battery bank will be at a much higher voltage than a typical inverter so tapping into that is more difficult. The 12V aux battery is easy to tap into but it is charged through a dc/dc convertor, this loses a tiny bit of efficiency but more importantly has a set capacity. I can't say for sure how much current you could draw from the 12V battery without overloading the convertor because I am not familiar with that particular model. A 500 watt inverter would be fine I am sure, but more than that I just don't know.


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## alwaysready (May 16, 2012)

Padre said:


> My new BOV is a civic hybrid...
> 
> I know. If you have finished laughing can we continue?
> 
> ...


I have a Prius V and am very interested in what people have to say. While I had thought of the benifits a hybrid could present in a SHTF situation (Barring an EMP) a generator was not one of them. Padre something tell me it would be foolhardy to attempt to take your man card.


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## hiwall (Jun 15, 2012)

> The two most prolific hybrid manufacturers on the market, Toyota and Honda, each have battery packs with around 100 to 200 volts. In the case of the 2010 Toyota Prius, however, the voltage sent to the electric motor can be boosted up to 600 volts through a voltage converter [source: Webster]. Since the battery packs used by most hybrids produce around 100 to 300 volts of electricity, they are deemed "high-voltage" and must be labeled as such on the parts of the vehicle through which this voltage flows.


http://auto.howstuffworks.com/fuel-efficiency/hybrid-technology/hybrid-car-voltage.htm


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## Tirediron (Jul 12, 2010)

the hybrid as a generator is an interesting concept, you would probably have to get a modified ecm for it to work efficiently as a generator , the electric motor/ generator is rated at about 13 hp, but I couldn't find any duty cycle information, apparently the battery is make up of 120 D cell batteries. interesting
https://en.wikipedia.org/wiki/Honda_Civic_Hybrid

why you kept a Dodge and sold the Tahoe, OH yea you could sell the Tahoe


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## Cotton (Oct 12, 2013)

I posted this link in another thread.

http://otherpower.com/

Select the discussion board (forum) then join up. If anyone can help with this the members can. Some of the people there have lived off grid for decades. More than a few engineers there as well. They helped me build solar panels from scratch years ago.


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## hiwall (Jun 15, 2012)

Does the battery charge off the motor or only off the self braking when you let off the gas? 
What convertor brings in 200 volts DC and changes it to 120 volts AC?
I don't see much value as a generator but as a cheap running car it should be good.


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## cowboyhermit (Nov 10, 2012)

hiwall said:


> Does the battery charge off the motor or only off the self braking when you let off the gas?
> What convertor brings in 200 volts DC and changes it to 120 volts AC?
> I don't see much value as a generator but as a cheap running car it should be good.


The batteries charge off the gas motor when necessary, the regenerative braking is just a plus.

High voltage DC inverters can be found or made but usually it is not worth it. All these vehicles have a 12V DC system already so it is easy to go hook up a standard inverter. The only issue is the capacity of the DC/DC convertor and this depends on the particular model. If you want more capacity then a larger or additional DC/DC convertor could be added.


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## labotomi (Feb 14, 2010)

hiwall said:


> Does the battery charge off the motor or only off the self braking when you let off the gas?
> What convertor brings in 200 volts DC and changes it to 120 volts AC?
> I don't see much value as a generator but as a cheap running car it should be good.


The motor charges the battery. 
Regenerative braking does help out a little bit but it's far less capable than the motor
.
All inverters convert DC to AC. Even AC-AC variable frequency inverters convert the AC to DC and then back of the desired frequency AC. There are standard ones on the market that can utilize just about any DC input voltage that's above the AC output voltage you desire. They're not usually used in residential applications but if you look at industrial suppliers you can find more information.

I'd have to agree with you on the limited potential as a generator. Maybe in an absolute emergency you could tap off the battery as cowboyhermit stated. The design of the system was more toward powering the car primarily and charging the generator secondly. Running a 98hp gasoline engine would use a lot of fuel for the limited generating ability.


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## Padre (Oct 7, 2011)

cowboyhermit said:


> Great idea, the main problem is that the cars actual battery bank will be at a much higher voltage than a typical inverter so tapping into that is more difficult. The 12V aux battery is easy to tap into but it is charged through a dc/dc convertor, this loses a tiny bit of efficiency but more importantly has a set capacity. I can't say for sure how much current you could draw from the 12V battery without overloading the convertor because I am not familiar with that particular model. A 500 watt inverter would be fine I am sure, but more than that I just don't know.


An engineer was able to do it, with his prius, simply (he says), during Sandy. It got a lot of media attention.

He was able to take off 1000W, and it required the hybrid engine to turn on to charge the battery twice an hour. He said over the course of a couple days of usage he used 6 gallons of fuel, which is likely more efficient than a generator because the generator is storing the power in the battery and only turning on when the battery goes below 50% capacity.

There are a number of pages about doing this inn various ways like this one http://priusgen.sandbox.org/ but I am not sure if I am up to the task myself. What I am more interested in knowing is: is it possible with my car's specs (not a prius), and if so what sort of equipment ought I have on hand if the SHTF to try this? I have a few guys who have some skills with electronics, but there is no way I am letting them near my car unless its an emergency.


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## Padre (Oct 7, 2011)

My specs for those who might know what these numbers mean... is that right? 20 kW, thats 20,000 watts? 

CIVIC Hybrid	
Lithium-Ion (Li-Ion) Battery	
Output (kW) 20	
Voltage 144 
Volume (Liters) 16 
Weight (lbs) 48.5	

Electric Motor
Permanent Magnet Motor	
Horsepower @ rpm 23 @ 1546-3000 
Torque (lb-ft @ rp 78 @ 500-1546 
Voltage Range 108V - 172V


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## cowboyhermit (Nov 10, 2012)

Unfortunately those specs don't really have what you need but from it I gather you have the "3rd generation", according to a quick search.

20kW is 20 000 watts, correct but you need to have the time component to determine how much energy is stored. 

It is surprising how difficult it is to find the right specs for these vehicles online.

The electric generator/motor in the new models is 17kW(23hp), that will provide a lot of power, likely more than any inverter you would purchase.

I have seen the prius emergency power stories and unfortunately they don't give details or do things in a strange way. That link you posted for example, imo that is not the way you want to go, no need to add a second set of batteries (in the ups) and he has to use a generator to get the thing going

So really there are several ways you can go.
1. Find an inverter that you can connect to the vehicle's high voltage lithium ion battery. This should be easy enough but not cheap and would involve some high voltage DC wiring. If the battery indeed is nominally 144V then parts should not be too hard to find.
This method allows you to tap the full capacity of the generator.

2. Connect to the high voltage battery as above but use a 144VDC to 12VDC (or other low voltage DC) then use a cheap inverter. This would allow you to use the full capacity of the generator depending on the size you buy.

3. Simply use a cheap, readily available 12V inverter attached to your 12V battery. The smallest ones can be powered through the cigarette lighter but anything with real capacity will need to be hooked directly either with some simple wiring or with clamps like booster cables.
This method depends on the cars DC to DC converter to determine how much you can draw and will definitely not have the output that the first method will. If the converter in your car has enough capacity for what you want to do this would be the method I would likely choose as it requires no modification and will be the cheapest option by far.

It may seem inefficient to use such a large gasoline motor for generating power but the hybrid component really changes things. When the motor starts up and the batteries are drained it is certainly not idling with a generator of that size. Even with a typical generator setup I am a big fan of using a battery bank to reduce runtime.


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## hiwall (Jun 15, 2012)

But in this scenario they are are only using the standard alternator on the motor to charge the battery, correct?
So the only benefit is the big battery, not the "generator".


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## cowboyhermit (Nov 10, 2012)

hiwall said:


> But in this scenario they are are only using the standard alternator on the motor to charge the battery, correct?
> So the only benefit is the big battery, not the "generator".


There should be no "standard" alternator, this is replaced by the electric motor/generator and the DC/DC convertor.

The DC motor also replaces the starter in many circumstances but they often have an old fashion one as well that will kick in when needed.


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## hiwall (Jun 15, 2012)

> There should be no "standard" alternator, this is replaced by the electric motor/generator


So the gas motor can spin the electric motors without the vehicle moving to act as a generator? I obviously have no knowledge of how these vehicles work but I like to learn stuff.


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## cowboyhermit (Nov 10, 2012)

hiwall said:


> So the gas motor can spin the electric motors without the vehicle moving to act as a generator? I obviously have no knowledge of how these vehicles work but I like to learn stuff.


There are different ways to do a hybrid system, some use motors at the wheels which is what you might be thinking of.

The Honda version has one electric motor/generator hooked directly to the gasoline engine. This has some drawbacks because with their particular setup when in all electric mode the electric motor still has to turn the engine over even though it freewheels.

I am by no means an expert on these cars though, just going with what I have picked up here and there and the basic components.


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## hiwall (Jun 15, 2012)

cowboyhermit thanks. We are kinda in the same boat. Where is this sites hybrid expert? Why hasn't Nakid recruited one?


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## Fn/Form (Nov 6, 2008)

There are DC-DC converters and DC-AC inverters that can make use of that voltage range. The DC-DC converter could help with 12VDC needs; however many are not very efficient.

Look at solar and even commercial inverters for the 150VDC+ input voltage. I used to work with some of the older inverters in that voltage range, but they weren't as efficient as the newer, high-freq inverters. We were just getting into the hi freq models when I left the industry. Some systems use "modular" inverter sections to add redundancy/scalability.

Proper fusing and safe connectors are huge, obvious needs. I am not sure if there are dangerous impedence/internal resistance issues involved with using Li-Ion batteries with some inverter designs.


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## Cotton (Oct 12, 2013)

Padre said:


> An engineer was able to do it, with his prius, simply (he says), during Sandy. It got a lot of media attention.
> 
> He was able to take off 1000W, and it required the hybrid engine to turn on to charge the battery twice an hour. He said over the course of a couple days of usage he used 6 gallons of fuel


I'm not being critical or derogatory. I simply don't understand where you're going with this&#8230; what are you trying to power and in what circumstance. This alone dictates how.

I read the description at http://priusgen.sandbox.org/. It was 2 years before H. Sandy! As far as the engineer during Sandy&#8230; There is no mention of the power lost starting an engine twice an hour. Not to mention gasoline couldn't be pumped at stations without power. How long did he run his test? Why?

During the 2011 tornado outbreak I saved 3 freezers full of food for 12 days with less than 9 gallons of fuel. Standard off the shelf 5kw gasoline generator.

What I'm asking&#8230; are you trying to save a freezer full of food for a few days? Are you trying to use up the last bit of fuel in your hybrid in a long term shtf situation before you dump it? What is the circumstance? Maybe a solar panel would be cheaper than the gear required for efficiently using up a few gallons of gas? Just asking?


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## LincTex (Apr 1, 2011)

A lot of 120vac stuff would still work on 144vdc. 
Mostly power tools, and other motor-driven kitchen appliances (they'll just run a bit faster)

What is the OCV of a Honda hybrid battery pack?


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## LincTex (Apr 1, 2011)

Hmm...apparently - there is no easy answer. The computer on board is always changing the amount of electricity drawn and the rate of re-charge.

http://99mpg.com/blog/batterypacksexpose/

At this point, the best you can do is what ever you can work from the standard 12 volt battery and an inexpensive 12vdc-to-120vac inverter, like the Prius people are doing. You are very limited in the amount of current you can draw from that battery. I would suggest using a 12v deep-cycle marine battery in parallel if this is your plan of action. That should reduce "start/run/charge" cycle times.

Trying to tap into your vehicles propulsion battery packs appears to be a far, far, far, far more difficult proposition than it would be to just use a small 4-cycle generator and have some stored gas.


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## LincTex (Apr 1, 2011)

This article says 180 volts....

http://www.homepower.com/articles/vehicles/hybrids/rebuilding-hybrid-vehicle-battery-pack



> Hybrid car blogs published plenty of warnings about getting electrocuted from the batteries. Since this was new territory for me, I took this advice seriously-but there is only one place on a battery pack where any real hazard exists: from voltage across the full pack, which can be up to 180 VDC.


 "That single location is easily found with a multimeter, and once you turn off the IMA pack's built-in circuit breaker and start unbolting the individual subpacks, the risk drops significantly since the sticks are only about 8 V each.

Honda designed the battery pack in an almost idiot-proof way. The terminal bolts and other fasteners are arranged so that it is easy to avoid touching two ends of any higher-voltage terminals at the same time. Common sense coupled with basic mechanical skills meet most everything else you come across during this task."


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## hiwall (Jun 15, 2012)

If it would work good, I could see some benefits to using the car instead of a generator. 
Car is very quiet.
Car is a common sight and would not draw attention like a generator could.
Car can still be used as a car, where a generator only has one use.

But the reality appears like it is not designed to play multiple roles. Too bad. Now Padre has that 'girly' car.


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## LincTex (Apr 1, 2011)

hiwall said:


> If it would work good, I could see some benefits to using the car instead of a generator.
> Car is very quiet.
> Car is a common sight and would not draw attention like a generator could.
> Car can still be used as a car, where a generator only has one use.


Notable points. 
As an aside, a person could take nearly any car/light truck and install a much larger alternator on it and accomplish nearly the same thing.

The aftermarket car audio/stereo industry has made it possible to install a very high output alternator on nearly any vehicle made.


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## Tirediron (Jul 12, 2010)

hiwall said:


> If it would work good, I could see some benefits to using the car instead of a generator.
> Car is very quiet.
> Car is a common sight and would not draw attention like a generator could.
> Car can still be used as a car, where a generator only has one use.
> ...


But you might have come up with a really great opsec method of generating power, a small car, like a geo metro set up to run some high output alternators, it doesn't need to be drivable it just needs to look some what decent and look driveable. the small 4 cycle engine is going to be more efficient and easier to muffle than a single cylinder generator, if you were really wanting efficiency you could recapture the heat for what ever, and you could house you batteries in the interior, if you put those decorative sun shades in all of the windows. ******* or what??


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## FrankW (Mar 10, 2012)

Padre said:


> That's what I am posting about...any one have any technical knowledge to offer about considerations I should make in taking power from my hybrid engine? I understand the how is a simple inverter run off the battery posts. Where should I look for specs on how much power the car needs vs how much it is safe to take off?


I dont remember which one, but there is currently an electrical car FS that is set up form the factory to feed electricity back into the house acting as an emergency generator.

it might be a good idea to find out which car it is and examine that set up


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## LincTex (Apr 1, 2011)

BlueZ said:


> I dont remember which one, but there is currently an electrical car FS that is set up form the factory to feed electricity back into the house acting as an emergency generator.


Nissan Leaf, that particular version is not yet available in the US

http://www.greencarreports.com/news/1079955_nissan-leaf-to-home-power-station-will-it-make-it-to-u-s

The DoD thinks it might be a good idea:
http://www.csmonitor.com/Business/In-Gear/2013/0124/Can-electric-cars-be-used-as-backup-generators


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## labotomi (Feb 14, 2010)

LincTex said:


> Nissan Leaf, that particular version is not yet available in the US
> 
> http://www.greencarreports.com/news/1079955_nissan-leaf-to-home-power-station-will-it-make-it-to-u-s
> 
> ...


It would be great if it had a combustion engine and generator. As it is you'd have to charge it up somewhere and then drive it to your home, use the energy and hope you still had enough power to drive it back and charge it up again.

Seems like a lot of trouble.


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## redhorse (Dec 27, 2012)

How about this? I know it won't power the whole house exactly, but the possibilities are endless.


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## LincTex (Apr 1, 2011)

redhorse said:


> How about this? I know it won't power the who house exactly, but the possibilities are endless.


It's OK... the feed rate needs to be increased in that vid.

These folks (and many others) make alternators that put out *serious* amperage:
http://www.zena.net/htdocs/alternators/alt_inf.shtml


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