Gas/Electric Hybrid Systems

Discussion in 'Electric Bicycles' started by SimpleSimon, Jul 21, 2008.

  1. SimpleSimon

    SimpleSimon Active Member

    Okay, this really started (for me, at least) with augidog’s “Creative Interpretation” thread, but I’ve been asked to start a thread, so I will.

    Combining the above with the ongoing thread post in the Electromotive thread;

    The second paragraph of that last post is a separate can of worms.

    I invite any and all ideas, critiques, addendums, whatever you might have to say. I will say this - such a system bulks up a good bit, although you might be surprised by how small/light it can be made if one is willing to spend the money (look at Matt Shumate’s electric recumbent).

    For my own purposes and needs, I want a trike. Either delta or tadpole, although I personally prefer a tadpole configuration. Delta trikes are MUCH more common, and much easier to get as already functional bikes. So, I am working on such a system plan, as I told Mountainman:

    I am, at this time, putting together a simplified plan to implement just such a system for a delta trike. It will be somewhat generic, as of course the individual component choices made by each builder will vary somewhat. The major system components are, however, pretty much the same as I envision it:

    1) 2 cycle gas powered portable generator, as light and physically small as can be reasonably achieved, capable of producing approx 1 KW;

    2) A battery pack - number/size of the batteries again being somewhat variable, but practically speaking capable of at least 24V, and a range of at least 15 km at full charge without the generator;

    3) Motor/controller capable of powering the drive wheel(s) with reasonable acceleration, and of maintaining 20 mph on level ground; and

    4) capable of propelling a 300+ lb load as described above - your average guy being around 200 lbs, the bike and system being another 60+, and a small payload capacity.

    Multiple gears, with electric power delivered through the bike's pedal drive train, are a plus; as would be regenerative braking. Lots of little add-ons that would be nice; for instance, a good, bright lighting system.

    Still working on the details at this time. Feel free to take the idea and run with it - from my point of view, the more bikes on the road the better, and such a system does not lend itself readily to abuse with high top speeds, etc.

  2. Mountainman

    Mountainman Active Member

    SimpleSimon -- I must say - this idea has sparked my minds eye !!! It has been A LOT OF FUN watching you develop your thoughts in regards to said project.. I wish you well and look forward to keeping informed on your progress.. I am also interested in either building up or buying one of these HYBRIDS someday.. Until then -- Happy Riding from - Mountainman
  3. mac66

    mac66 New Member

    Hey, my first post.

    I am here primarily to learn more about motorized bikes because I had an idea of a putting together a hybred pusher motor. Low and behold there are others out there with similar ideas.

    My idea was to have either have an direct drive electric motor or a hub motor on a single wheel trailer with a small gas generator. My thinking was the electric would be stealth/quiet mode, the generator would simply recharge the batteries when needed. Then I thought, why not use the generator to recharge while in use which would give one real long range. One could use the battery in the city or at night (stealth mode) crank up the engine out on the highway. Or of course, take the trailer off and have super stealth mode.

    Stealth mode IMO, is important at least here in Michigan, because the laws are somewhat ambigious about motorized bikes. The police here pretty much ignore small electric and gas scooters/go-peds unless you are being stupid on one.

    Anyway I am interested to see how this thread develops over time.

    BTW, back in the day, someone was marketing a tiny 300-500W 2 cycle gas generator that was about 8" square. It was maketed in camping mags etc shown with a coffee cup for scale. Something small like that would be a interesting choice.
    Last edited: Jul 22, 2008
  4. vegaspaddy

    vegaspaddy Member

    delta trike is my project for next year,

    here a links to two small generators found all over the internet

    i already have my tadpole electrified, but if it was able to charge the batteries and switch to gas that would be way cool, not sure if i could retrofit this one, hence the new build next year....

    need to save money and convince my wife !!!!!!!!!

    watching closely,
  5. SimpleSimon

    SimpleSimon Active Member

    Good to see some interest. I like the trailer idea, although a single wheeled trailer requires a lot more complex hitch to remain stable. I also REALLY don't like the pusher concept - it is in effect an articulated vehicle with all power inputs in the rear portion, all steering inputs in the front section. Doable, but it complicates your hitch point issues a good deal.

    All that said, a very small electric motor mounted behind the seat tube with a compact jackshaft arrangement feeding a free-wheel capable chain ring inside the main front chain ring(s) can easily provide the desired power, and let you just pedal it any time you wish, and still leave you with all of your shifting capabilities. If you set up your power trailer with a couple of good batteries along with the generator, all that runs up the hitch tube is your power/controls cable.

    Northern Tool sells (for $129) a small two-cycle gas engine powered 1 KW portable generator. Really good hi-output electric motors aren't cheap, but they aren't prohibitive either, and they can be smaller than a pop can.

    Thanks for that link to the other site selling that generator. Even better price.
    Last edited: Jul 22, 2008
  6. vegaspaddy

    vegaspaddy Member

    there is a build around here which istumpled on a couple of months ago of someone living down in florida who had a genator hooked up to his electric system, i dont think he was using it to actually power his machine just to keep his batteries charged, sort of like regenerative braking. Will try to find the link and post.

    p.s. have you seen the setup staton is working on.
  7. mac66

    mac66 New Member

    Last edited by a moderator: Oct 30, 2008
  8. vegaspaddy

    vegaspaddy Member

  9. vegaspaddy

    vegaspaddy Member

    still using batteries but,

    As you can see, this is a pretty simple and crude setup at the moment. Just a power hub mounted on the trailer, with 4 7 a/h batteries. Then there is a 31cc trimmer engine driving a 10 amp permanent magnet motor to recharge the batteries, and run a few accessories. (like the 55 watt halogen headlight I have yet to install) I run the engine up till the motor is putting out about 56-60 volts. As long as the biike is using power, it doesn't seem to bother the batteries. The whole generator setup weighs maybe 12-15 lbs. Also I have a dp/dt switch that kills the engine, and discnnects the generator for those instances when I want to glide soundlessly past some one. Flip the switch, and the generator restarts the motor after the situation is past.

    second thread reading,

    so it seems there are a couple of generator to battery to motor builds exist, cutting out the middle man (the battery) is going to be the HARD part.....
    Last edited: Jul 22, 2008
  10. SimpleSimon

    SimpleSimon Active Member

    mac66, that mini-generator you posted a pic of is essentially identical to one I used extensively in South Africa/Lesotho/Botswana 30 years ago. The one I had there was built by a company called Hedley, in South Africa, and was about 20 years old when I got it. 4 cycle single cylinder 28 cc engine, it was set up to make 12 volt or 220 volt power, normal output was 350 watts. The single most reliable small engine I've ever used - I put probably 150 hours a month on it or more, and all I did was change the oil every 500 hours of operation, wash out the air filter element, and keep it fueled up. The guy I bought it from (for R20.00) told me not to ever let it run dry, as it would run really lean and overheat, and blow the head gasket. Said it had happened to him twice, with no other damage. Wish I still had it, but it was taken by somebody in the SADF patrol group I fell afoul of in western Botswana (they claimed I was in eastern SW Africa).
  11. mac66

    mac66 New Member

    Eegaspaddy, the system from station-inc that is being developed looks interesting but bound to be expensive.

    The other one using the weed wacker engine and a 10 amp motor is pretty much how I envisioned my idea. I think I will start looking into doing something along the same line.

    Simplesimon, my recollection was that the Power Pony was chinese made. I could be wrong however. The last time it was offered for sale in the US that I could find was in 1998. I've been unable to find one or find out who made it. Looks like I need to start looking in S.Africa. I probably would have more luck finding a used Honda EX350.
  12. lfairban

    lfairban New Member

    Dissagrement and a suggestion.

    I don't think that your legal arguement will stand. The law does not say directly powered only powered or something to that effect. If the generator is on the bike it would be the same as if the engine were directly connected to the wheels. If you carry the generator as baggage then stop the bike at a rest stop, fire up the generator and re-charge, you might be OK, but then you would still need the batteries.

    Your criticism of SLA batteries is correct, but for low price application they are acceptable. Lately, the alternatives such as NiMH, Li-ion, Li-ion polymer and LiFePhosphate are becoming available. I just bought my wife a bike with Li-ion polymer batteries. So far, so good. I think the battery pack is worth around $300-$500.

    I believe I have seen hybrid autombiles discribed as using, "through the road" charging. I think what they are doing is using regenerative breaking capable motors along with a conventional transaxle motor. When the batteries need charging the motors go into regenerative mode while the engine is on.

    I don't see the need to add a generator to the overall weight when you can get the motor to provide the same function. You can still get by with minimal batteries, 7Ah should be more than enough. 3Ah might even work. I think the Bionx has a rear hub motor that will provide various levels of regeneration.

    You would use the electric motor to lanch from stoplights and at low speeds. When you get up to 17mph on a fairly open stretch, start the gas engine. You can speed up to as high as you need. Then if the battery needs re-charging, apply light re-generation until the batteries are charged.

    Repeat as necessary.
    Last edited: Jul 23, 2008
  13. SirJakesus

    SirJakesus Guest

    Yeah a GEBE system and a bionx rear wheel would work great. But it's a rather expensive venture.
  14. mac66

    mac66 New Member

    I am in the process of building a hybrid pusher trailer. Basically I took a 36v/350W scooter, stripped it to the frame and took off the front wheel and fork.

    I rebuilt a Homelite 25cc gas trimmer engine, bought a wind generator motor off of ebay and am configuring it like ibdennyak did in this thread:

    This photo is his. I am naming it the Denny Hybrid in his honor

    Next steps:

    1. Figure a way to hook the gas engine shaft to the electric motor shaft
    2. Figure a way to mount both motors on the scooter frame.
    3. Figure out the wiring. I have retained the controller for the scooter which will allow the use of a number of functions. I would like to hook up a gauge or meter to keep track of the status of the batteries so if anyone has a suggestion for a specific gauge or meter let me know what and where to get.
    4. Figure a way to hook the "trailer" to the bike.
    Last edited by a moderator: Oct 30, 2008
  15. ibdennyak

    ibdennyak Guest

    Just what I need.....more trouble. Now they're naming it after me. :cool::lol:

    Working on a pm on how I did the various connections. Keep an eye out.
    Last edited by a moderator: Oct 30, 2008
  16. fredie

    fredie Member