My car by emergency generator

Discussion in 'Equipment & Survival Kits' started by Padre, Nov 9, 2013.

  1. Padre

    Padre The Black Pilgrim

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    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?
     
  2. Grimm

    Grimm There is a place in Hell for me...the THRONE.

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    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!
     

  3. Geek999

    Geek999 Member

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    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.
     
  4. cowboyhermit

    cowboyhermit Supporting Member

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    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.
     
  5. alwaysready

    alwaysready Well-Known Member

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    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:eek:.
     
  6. hiwall

    hiwall Just walking at the edge of my grave

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

    Tirediron RockyMountainCanadian

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    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:coffee:
    https://en.wikipedia.org/wiki/Honda_Civic_Hybrid

    why you kept a Dodge and sold the Tahoe, OH yea you could sell the Tahoe:D
     
  8. Cotton

    Cotton Supporting Member

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    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.
     
  9. hiwall

    hiwall Just walking at the edge of my grave

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    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.
     
  10. cowboyhermit

    cowboyhermit Supporting Member

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    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.
     
  11. labotomi

    labotomi Well-Known Member

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    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.
     
  12. Padre

    Padre The Black Pilgrim

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    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.
     
  13. Padre

    Padre The Black Pilgrim

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    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
     
  14. cowboyhermit

    cowboyhermit Supporting Member

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    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:confused:

    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.
     
  15. hiwall

    hiwall Just walking at the edge of my grave

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    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".
     
  16. cowboyhermit

    cowboyhermit Supporting Member

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    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.
     
  17. hiwall

    hiwall Just walking at the edge of my grave

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    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.
     
  18. cowboyhermit

    cowboyhermit Supporting Member

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    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.
     
  19. hiwall

    hiwall Just walking at the edge of my grave

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

    Fn/Form Function over Form

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    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.