Quote:
Originally Posted by rmay635703
To achieve 50% efficiency you CAN NOT DO THAT, period!
Those motors are designed to work at ONE OUTPUT SPEED AND POWER VALUE.
Motors that vary output tend to all universally be below 30% efficiency, most being below 25% in real world. (and thats modern fuel injected, not a small gas engine).
[clipped from quote]
Thus a generator powering an electric motor decoupled so it could only run at its most efficient range could likely still operate about 65% more efficiently (even with losses) than a classic variable throttle motor running through some sort of gear reduction system.
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Let's say this is planned out, One output speed, could be tied to a small range, say 60-65mph. One power level, we could fix the throttle to its most efficient point to provide this. Couldn't we?
This would be for a long ranger EV. I've thrown the thought around of having a 100 mile EV without any additional power sources but driving it to Madison, WI for the Green Drive Expo instead of trailering it behind a tow vehicle. I figure something like this 16HP 6500 watt genset
16 HP, 6500 Rated Watts/7000 Max Watts Portable Generator - EPA would be enough to stretch the range in the most aerodynamically efficient and lightweight vehicle possible to where if driven efficiently enough at a slightly slower speed than the rest of traffic that it would extend the range just enough to make it with a single extended break halfway through the trip. ...but if it could be geared to put the engine speed in its sweet spot and throttle adjusted to a fixed position to only provide the power level to the point of maximum fuel efficiency, could this work well? 16HP at say a 70-80% load connected to the ground is going to be much more powerful than trying to find the maximum the genset can continuously squeeze out comfortably(probably not the full rated 6500 for the full distance).
BTW, I am more electrically capable than mechanically capable so I probably wouldn't figure out how to connect the engine to the ground but more curious than anything. Mostly carrying the thought as a 'I'd try this' sort of one-off hobby try. I'd probably just connect the generator to an isolated amperage adjustable charger and work from there. If I really wanted to do this for a longer trip, I figure I'd need two of these generators (with two isolated chargers) to provide adequate power since one will leave someone in an empty battery hole after not too long of traveling down the highway.