# Built in Recharge option



## skeeterb (Feb 6, 2009)

I thought of something a few days ago. What would you guys think about putting a generator (120VAC converted to DC). Take the ICE engine off the generator and find a method of tying the generator input shaft to the motor and have the generator constantly recharging until the batteries approach full. find of way to uncouple the generator from the motor until the batteries get to a specific discharge level and recouple the generator to the motor. What do you guys think?


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## Anaerin (Feb 4, 2009)

I'm a little confused. 

Are you talking about hooking the alternator from the Generator up to your drive motor and trying to get power out that way? If so, it won't work. It's an attempt at an "Over Unity" device. As the Alternator turns, it causes a drag on it's input, which would cause your motor to use more power to drive the alternator, negating any potential power gains you might get. See also: Perpetual Motion

Or, are you talking about hooking the ICE from a Generator up to your drive motor to generate power for the batteries when "idle"? If so, that could work, as long as your motor/controller system supports Regen, however the Generator already comes with a very nice Alternator sized just right for the ICE it's packaged with, and you would almost certainly be better off running the Generator as-is and charging the batteries from that. See also: Series Hybrid


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## skeeterb (Feb 6, 2009)

I meant REMOVE the ICE from the generator and find a way to couple it to the drive motor. Not put the ICE from the generator on the car. It wouldn't be a pure EV if it had any ICEs, then it would be more like a hybrid. I don't want a hybrid, just a pure EV that generates some of its own power to restore some power back into the main battery pack.


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## Anaerin (Feb 4, 2009)

The no, it's not possible. At it's simplest, you're looking at a perpetual motion machine, which can't possibly work thanks to the laws of thermodynamics. Nice try.


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## kittydog42 (Sep 18, 2007)

The reason that this doesn't work the way that you think it should is because it uses more power to drive against the generator than the generator would create in return. You would have a net loss of power. Where it can work is when you use it for braking energy, as it will create some power while also providing stopping force, which you would be doing anyway with the brakes. This is why EV's have regenerative braking. The only way that you can make that work off of the motor shaft is if you decouple the generator for normal driving, and only couple it when you need braking. 

If you don't believe us, try this experiment - rig up a generator to a stationary bike, so that you turn the generator with your leg power. Hook up a small sized load, say 1000W, to the generator via a switch. Get the pedals turning good and fast, then flip on the switch. I think you would be lucky if you came up with anything short of two broken legs. That would demonstrate how much resistance generating power creates.


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## ice (Sep 8, 2008)

good illustration...they are right!


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## EVF (Jan 18, 2009)

_Hello skeeterb , Sorry but they are right and at this time our limits are held in place by certain proven laws . However if you could get past the friction drag coefficient aspect of generating power under load without substantial drain on your pack you might be able to extend the range. You must understand and except the laws of thermodynamics before ever getting or going past them. By attaching the term of text (that is the word law ) to the idea or understanding of something is mint to make the idea or understanding immoveable / unchangeable . However the first textual term that something has is that of Principal in the aspect of how it works , and is not as permanent or unchangeable as when the word LAW is attached to it . It is because of the widely and commonly accepted view of the facts that lends itself to being a law instead of only a principle . I tend to like the term Principle because it simply explains how something works and allows or does not restrict the mind or imagination from freedom to entertain innovations with the Principle of how something works . Albert Einstein once said — when we accept our limits we go past them — _


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## Telco (Jun 28, 2008)

Running the generator with an ICE really isn't a bad way to go though, since the ICE will be optimized to run with the generator's optimal speed for power generation. It's far more efficient than using an ICE to move the vehicle directly as the ICE must make power across a wide RPM band but is only efficient in a very narrow band. This is the approach the Chevy Volt is taking, and according to that car's fan site it's expected to get roughly 60MPG in ICE mode once the 40MPG EV-only range is depleted. Whether that's true or not remains to be seen. While EV only would be the most desirable, it would be far better to run a serial hybrid at 60+MPG than to run a standard ICE in a similar vehicle for 30MPG. And, it's very possible for someone to do.


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## jlsawell (Apr 4, 2008)

Telco said:


> Running the generator with an ICE really isn't a bad way to go though,


The guy who used to own my local wreckers advised me to look into the Honda range of generators. He said there is one that will fit inside the spare wheel hole in the trunk/boot which you could use as an emergency range extender. Small but powerful.

I haven't looked into it, but it sure is an idea.


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## cdbldr (Feb 4, 2009)

We were talking about this in another thread--annoying how that happens! Anyway, a 1-2kw Honda generator only weighs 25-50 lbs and is quite compact and quiet. Honda says the 1kw uses .6 gallons for 8 hours of run time. Is it possible to engineer a Volt-type system with it, where it charges your pack as you drive? My EV range should be enough for 90% of my trips, but on a slightly longer drive, would 1-2kw be enough to maybe extend my range by 20-30%? Is it possible to hook this up so that it is charging while you are driving--like maybe you just plug your onboard charger into the 120v outlet on the generator and go? Then if you knew you had a longer day ahead, you could start it up when you left home, and leave it running as you drive/park/errands etc. Especially if you're doing in-town or stop and go driving, you'd be giving the generator more time to charge you up relative to how much electricity you're consuming. And you could leave it running even while parked.


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## Anaerin (Feb 4, 2009)

The concept is called a "Series Hybrid", and is what the Chevy Volt is supposed to be. It's workable in theory, provided your charger and controller will work at the same time (The power draw from the controller to the charger at peaks may cause problems with the charger trying to provide more power than it's meant to).


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## skeeterb (Feb 6, 2009)

was that Zero Point six gallons or six gallons? if its 6 gallons that still seems to be pretty reasonable.


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## cdbldr (Feb 4, 2009)

According to the Honda website, for the 1kw generator, it's .6 (point six) gallons for 8 hours. I bet that's under light load, and that the motor revs higher when more output is called for. That's the way the generator in my old RV worked--the more electricity you needed, the higher it would rev until it was at max output. But still, that's not much gas. And it's a really small unit--only 25 lbs. Even if I can't have it running while I drive (my tech knowledge is too limited to know how to hook that up) I might still install one as a backup to use if I'm parked or stuck somewhere without a plug.


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## dtbaker (Jan 5, 2008)

cdbldr said:


> ...would 1-2kw be enough to maybe extend my range by 20-30%?


lets say you are driving along at a nice steady 35-40 mph... you probably have just enough 'regular' battery to do that for an hour. If you also had a 2 kwhr gen running, feeding the recharger for that hour, you would have added at MOST 2kwhr (with perfect efficiencies). The 2kwhr you added might get you another 5 or 6 miles.... so , maybe an extra 10%-15% range.

but, you wouldn't have perfect efficiency charging, and a slight reduction from added weight, and far less GREEN.


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## GKnightBC (Sep 10, 2008)

cdbldr said:


> <snip> Even if I can't have it running while I drive (my tech knowledge is too limited to know how to hook that up) I might still install one as a backup to use if I'm parked or stuck somewhere without a plug.


I can that being usefull, for sure, at a stop but certainly, at 1kw, it could not get you much more distance since, assuming 250Whr per mile, one hour of generator only gets you 4 miles. Sort of like limping to the next power plug! 

Has anyone looked into Propane generators for the same use? I would think, since the exhaust is water, that they might more of a 'greenie' choice.


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