Comments 16
  1. — Ken    Apr 05, 2008 00:50 AM    #

    In regards to your comment on the idea of using an electrical generator to power or recharge the battery, there are very efficient 4-stroke generators now available that can produce the approximate 10kW of power needed to power a car. If however, you used the battery as the prime supplier of electricity and used a smaller more efficient generator to produce electricity it could extend the range of the car with out adding significant weight. Imagine using your electric car to drive 200 miles. While you are driving, the small generator is slowing the rate at which the battery is being drained and when you stop for a lunch or bathroom break the engine continues to run (automatically) recharging the battery.

  2. — Greg Coleman    Apr 08, 2008 22:50 PM    #

    You might want to check with the Controller manufacturers. I don’t think they want high charging voltage going through them, while the car is going down the road.

  3. bob    Apr 12, 2008 21:32 PM    #

    the gen idea is not that far out of reason. Forget the batteries. Trains use the setup to pull very heavy loads. You could use an ac motor since you have a revers gear in your car, you do not need to use a dc motor. You could also try hooking up your catalytic converter into the exhaust line, but may need a free flow muffler. Your gas usage would be determined by gal/hr. City driving may not be to good, but highway comuting should be really good. In the end, you don’t know if you don’t try.

  4. — charlie    Jun 22, 2008 18:12 PM    #

    So, I was a car service driver in New York for about six years and got sick and tired of paying for ever increasing gas prices and fixing my car (I will never again buy a front wheel drive Cadillac my 2001 DeVille ate up $50,000 in maintenance in just one year, Northstar sux). Last year I moved to the Lehigh valley (by bicycle) and don’t really drive much any more. A couple of weeks ago, I went home and picked up my trusty old ’96 Town Car, and plan to use it to go to and from New York, for visiting family and such. It’s about a hundred miles each way, and I’m not really impressed with battery performance, and I expect I can easily generate 10kW using the old 4.6L V8 that it came with. The question at hand is are there motor/controllers available that can push that kind of weight around in the 12-24V range, while I get my backyard flex-fuel turbine generator working?

  5. ebikehub    Jul 05, 2008 13:33 PM    #

    check out the ebike forum

  6. — Ray Isham    Jul 27, 2008 08:23 AM    #

    Do not convert to dc use a phase converter and keep ac power This generator is powered by a Briggs & Stratton 1450 Series™ engine. A 5 gallon fuel tank with fuel gauge allows for a 10 hour run time at half-load. 5 gallon per hour at 55 mph give you 550 miles at 5 gallons = 110 mpg. could be done. Not a turnpike car.

  7. Jerry    Jul 27, 2008 09:12 AM    #

    Hi guys,

    Sorry, but you need to do a bit more explaining and calculating than that.

    How many amps does “half-load” deliver to the motor? And we are talking DC amps at a high enough voltage (>144vdc) to aid in powering the motor and/or charging the batteries. A 10kW backup generator is not going to be able to deliver 10kW of DC power to the battery pack.

    The motor and controller want DC, unless you’ve spent the $10k or more and bought an AC system. Even with an AC system it typically converts DC from the batteries to 3 phase AC, which means you’ll need to sync the output of the generator with that.

    Like I said above it’s possible to rig something up but it will be polluting (as compared to a car’s gas engine), you’ll be hauling extra weight which reduces overall vehicle efficiency, and there will be a fair bit of extra wiring and complexity. No way are you going to see 110mpg.

  8. — Scurvy    Jul 29, 2008 14:45 PM    #

    I would not use a generator as a replacement for the batteries, but solely as a range extender in motion and battery recharger while parked. Most generators also are heavy because they are lugging around a starting battery (I wonder where we could find one of those) and a heavy reinforced cage.

    A good diesel generator (using WVO) consumes about 0.1 gal/kW/h. As an example, imagine a 3kW genset on a trailer with a larger fuel tank and wired in to the vehicle (I know, easier said than done).

    Using a required power estimate derived from your articles for a fairly nice setup (J150 batteries, 200W/mi, 6kW/h at 30mph, 60 mile range) range would just about double (6kW off the pack vs. 3kW pack + 3kW generator per hour), maybe even more so before the battery ran out as you’d be pulling less power off them though I suspect the extra power would go to towing the trailer.

    Doubling range would get you 2 hours drive time using 1.2 gallons fuel going 120 miles for about 100mpg. Using the additional space on a trailer for an additional battery pack with a parallel connection to the vehicles pack could potentially quadruple your range (120 mile range using 6kW EV vs. 240 miles at 3kW) for the same 100mpg.

    While those numbers seem nice, remember that it is at 30mph, which while normal for a daily commute is not entirely conducive to long distance travel (unless you’ve got time and a hankering for sightseeing). Using the EV calculator, I get about 350Wh/mi at 60mph, which equates to 21kW/h giving a range of approx 35 miles with one pack and 70 with two. The same 3kW genset increases range to 40 miles with one pack and 80 miles with two at about 200mpg. A larger 9kW genset would increase range to 60 miles and 120 miles respectively at about 67mpg.

    OK, so at slow speeds you get great range at great efficiency, but it’s slow. At fast speeds you only get good range with good efficiency, but it’s faster. And while overall it’s not stellar, it’s a necessary evil if you want to take your car long distances. Sure, you could rent, but what about when you get there? You’re stuck with the ICE car. This way, you only burn the fuel getting from one distant locale to the other. Once you’re there, take off the trailer and you’ve got your eco-friendly EV for the duration of your stay. You’re still getting better milage than most cars, you can run it off WVO to make the oil barons weep, and you have the option of charging in out of the way places (try taking your EV camping!).

    Another suggestion would be to get a larger diesel genset for greater range. Sure, the milage would suck, but just stop every couple hundred miles at a fast food joint and steal their used fry oil.

  9. — Jeremy W    Jul 30, 2008 14:22 PM    #

    You are right and wrong about generators outputting AC power. the do put out ac at the plug in part but not as a first step. the generator produces dc which then uses a modified version of a DC to AC power inverter (the kind you pulg into your cars 12 volt power socket to power your laptop and power tools on the go). I have one and i took the DC to AC inverter out of the equation and i am going to measure the voltage(hoping it is 12 volts) and work on an idea i have going. A friend of mine who owns a local car parts store got a shipment of promo products last week. they are 12, 24 and 110-220 volt high power relays. He has 2 types. One has a control wire that closes a circuit and allows current to flow when it receives a 12 volt power signal(both the 12 and 24 volt have use a 12 volt control wire). the other opens and circuit and stops current flow when a 12 volt power signal is applied to the control wire. I am going to use both types(one attached to each battery). when i flip a switch and apply power to the wires the relays will move to one position and allow the pack to produce the necessary voltage and amperage used by the EV. when the switch is off the batteries will be connected + to + and negative to negative to produce 12 volts DC(or 2 batteries connected in series and each 2 battery pack connected in paralled to produce 24 volts DC) and the generator could be used to charge the batteries. You could put this on a trailer and significantly extend the range of an electric truck. the trailer could contain the secondary battery pack and when the primary pack on the truck runs out a heavy duty disconnect could be connected from the trailer to the truck and the secondary could run the truck while another disconnect could charge the primary battery pack in the truck which would use the same relay setup. I have no idea of the exact gas mileage but it is a 5500 watt AC generator so it has about 500 amps of output power at 12 volts DC. under full output it can run 25 hours on a 5 gallon tank of gas. An average Lead Acid EV battery(deep cycle high amp marine or car type batteries) has about 600 to 700 amps and most people only discharge them to about 400 amps. To be on the safe sid we’ll say the discharge the batteries down to 500 amps. the generator would be inactive until you decided to charge the primary pack. At 144 volts that would take one hour per battery or 12 hours for twelve 12 volt batteries. if you attached the motor directly to the drive axle and skipped the gear reduction step(i would personally do this because at an average speed of 70 miles per hour the motor is only running a 300 or 400 rpms and only 30 to 50 amps of draw for a 144 volt system)(not recommeded for EV’s used for 30 to 40 mile commutes because of extremely high top speed)then you could drive for 10 to 12 hours(assuming 500 amp max draw per battery) on the secondary pack and when it runs down pull over and switch connectors and switches to charge the secondary pack and run off of the primary pack. as long as you have fuel then you can keep going with minimal interruptions. the range in miles is potholed with too many variables but you could probably run for 00 hours on five gallons of gasoline(this is on the safe side because under near perfect conditions you could probably run 36 hours on five gallons of gas(the primary and secondary pack could be charged once each using five gallons of gas and the primary pack could be fully charged before you leave meaning you could run the primary, then the secondary, then the primary before you ran out of power), try that with a car or truck and see how close you come). And on the up side if you stop at a hotel along the way(i hope you wouldnt drive that many hours without doing something like that) then you could plug your onboard charger into the wall outlet and charge your primary and secondary battery packs there meaning you would use way less gas(and keep the other guests happy by not running a generator while they try to sleep). I am doing this not because i haul stuff cross country but i do go down remote roads with no way to recharge my battery if it runs out of power and if it works then i could go anywhere i wanted without much worry except for paying 20 for gas but thats no problem because i have a good job.

  10. — Scurvy    Jul 30, 2008 15:48 PM    #

    Where in the blue blazes are you getting a 5500W generator that runs 25 hours on a 5 gallon tank of gas? That’s an overall conversion efficiency of 76%. That’s twice as efficient as physics allows for a heat engine!

  11. — Bruce    Aug 30, 2008 19:30 PM    #

    How would I wire a generator into my 120 volt battery pack? Do I use the battery pack as a buffer? How would this affect my controller? Thanks,

  12. — Dan P.    Aug 31, 2008 10:18 AM    #

    Plug the batteries charger into the generator; very wasteful and inefficient.

  13. — Jason    Aug 31, 2008 15:04 PM    #

    Not for nothing but there are many ptifalls to the plan. HOwever there is also tremendous upside could the issues be solved. Everything now is as currently mfg’d for other applications, as poitned out if a train can do it so can a car. Wieght, emmsions, fuel consumption all are valid issues. However the idea with some if’s thrown in is great one. Were I loaded it is what I would be building. Don’t forget DC brishless gens are avaiable and produce quite a bit….

  14. — DavGreenberg    Sep 04, 2008 16:27 PM    #

    Hi, It’s not a simple problem, or simple solution. Things from life style to the way we look at things will have to change. But first I would go with a diesel and an A/C system, higher voltage. second Talk is great but to get out there and put the volts to the on the road, so to speak. The reason I would go with the diesel is because it can and was designed to run on veg oil, come on we can get that anywhere right? make a deal with your local restaurants and co op with other people if you have too. any way just had to say something after reading a lot of good posts, its an awesome start.

  15. — Steve Hz    Dec 18, 2008 00:31 AM    #

    Greetings all. I am posting in reference to using fuel generators to power an electric car. It’s already being done in a way. Check out the Oskosh trucking company’s ProPlus system:

    Okay, so I am just an average Joe here but think about it. Suppose we were to get away from insisting this needs to be done immediately for our commuter cars. How about if a move was made to produce a pickup truck type or larger vehicle for the farm/RV/construction/police command post vehicle market. Think about it, how beneficial would it be for these industries to have transportation, cargo capacity and a power supply rolled into one vehicle. Say this vehicle caught on for the next several years. Sure we would still be dependant on fossil fuels, be it gas, diesel, LPG or propane, but in the mean time we would be perfecting our ability to manufacture all aspects of an electric vehicle. The existing automobile industry would ease itself into manufacturing, selling & maintaining these vehicles. The generator technology would move to manufacturing “clean diesel” generators (like the new VW Jetta clean diesel car). People & industry would tinker with perfecting not only the vehicle but also the power supply. Ultimately, the power supply could be modular in the sense that each industry would use what ever fuel best suits there needs. Here’s the light at the end of the tunnel, some 10 or 12 years down the road (pardon the pun) either the batteries will get better or the perfect “fuel cell’ will be developed. BOOM…overnight our obligated dependency on fossil fuel goes away and the population is driving vehicles that, at their discretion, can change one modular component to upgrade to the new technology while still driving the vehicle that they have. We would have the ability to choose how fast we wanted to make the switch. The ancillary benefits would include that we would have been producing & perfecting “electric cars” for 10 – 12 years and the generator industry would have devoted 10 -12 years of research and development to perfect their product..

    The initial vehicle I picture is some thing like a long bead ¾ ton pickup truck and instead of a tool box just behind the cab there is the generator. Now the space under the hood for the conventional motor is free to be used as the tool box or storage space. Manufacturers are already putting trunks in trucks, right?

    I should put in a disclaimer here. I am not connected to any of these industries and do not stand to benefit from any of this. In fact, I am a dentist but I have been kicking this around in my head for some time. I was a child during the oil embargos of the 1970’s. We were driving around in gas guzzlers and we were one of the strongest nations in the world but yet we were obliged to the few countries that held all the oil. Thirty years later, what has changed

    Please, I would be very much interested in your feed back. Shoot holes in this idea or tout its benefits. I hope this makes for some interesting discussions. Maybe the forces to be might notice. Thanks for listening to my two cents worth.

  16. Kyle B    Dec 18, 2008 19:00 PM    #

    Steve – That Oshkosh military vehicle looks extremely heavy – I would guess over 100,000 pounds. Diesel-electric locomotives use the same setup to eliminate the transmission/clutch/gears issue – not for pure economy sake. Getting a million pounds moving from a dead start, and then cruising at 65 miles an hour is easy to repeatedly do with an electric motor direct drive.
    So I think that other than the ultracapacitors, this is not any new technology. I have not heard of anyone who has cheaply scaled up ultracapacitors, so if there is a breakthrough there, then that would be the story here – replacing heavy batteries with light caps. And caps can handle all kinds of abuse, whereas my Universal Batteries did not handle my addiction to torque.