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Totally fair. My thinking is that means you could lug around a lot less battery weight (ie, make the all-electric range 60 miles or so), basically just enough t

Totally fair. My thinking is that means you could lug around a lot less battery weight (ie, make the all-electric range 60 miles or so), basically just enough to complete the average amount of driving a car does in a day and operate on the assumption that most cars would get plugged in every night. In return, you'd get the ability to use the existing energy distribution infrastructure built around roadways (ie, gas stations) whenever you wanted to drive your car further than it could go on a charge. I'd also assume that the ICE/generator combo could be tuned to operate entirely within whatever window results in highest efficiency for the ICE engine, which should be a notable improvement on the way ICE efficiency varies by speed in traditional cars. I'm not saying that there aren't tradeoffs, just saying that it feels like an interesting idea. Enough so that I'm not at all sure why it didn't take off.

TylerE 3y ago
If the engine is able to always operate at peak efficiency, there is little reason to bother with batteries beyond a bit for handling transient peaks. I guess what it comes to down for me is that the hybird as you described, while it has advantages over pure ICE, it's sorta the worst of both worlds - all the moving parts, all the complexity, the fire risk from both li-ion AND gasoline, more expensive (since two drivetrains, essentially). A constant RPM motor for an extended period isn't a super enjoyable sound, either.
- sjm-lbm 3y ago
  > If the engine is able to always operate at peak efficiency, there is little reason to bother with batteries beyond a bit for handling transient peaks. My thinking here is that most of these theoretical cars would spend a good part of their life only operating on battery power - basically, all of the home-to-work-to-supermarket-to-home trips would be pure electric in my mind. So much so that I've wondered if the ECU would need to occasionally run the ICE for a bit just to make sure it doesn't ever spend so much time without being turned on that entirely different problems arise. > it's sorta the worst of both worlds I get this. This idea is very much the best of both worlds/worst of both worlds depending on your point of view. > more expensive (since two drivetrains, essentially) I'm not sure about this. I think the right comparison here is to imagine a battery that has (say) 25% of the range of a Model 3 battery, but is (say) 30 or 35% of the cost. Based on EV battery replacement cost, could you buy a cheap 3-cyl ICE engine and generator for that? Intuitively this feels possible, though I'll admit I don't have access to the data to be able to say, for sure how these costs would compare at scale. > A constant RPM motor for an extended period isn't a super enjoyable sound, either. The sound should be similar to the sound a pure ICE car makes on the freeway when on cruse at a constant speed and not changing gear. Yeah, you'd need to tune the exhaust to make sure the sound is pleasing, but this feels like a solvable problem also. (As an aside, sorry if it feels like I'm hassling you. I'm honestly not, this is just an idea that has lived in the back of my brain for a bit and I'm enjoying the discussion.)
  - TylerE 3y ago
    An ICE places a lot more constraints on design and manufacter...since it has to be behind a firewall, it's large, it has all kinds of fluids that need routing out... it's a nightmare. For comparison a typical EV battery is just a bunch of bricks inside the skateboard base.

TylerE 3y ago

If the engine is able to always operate at peak efficiency, there is little reason to bother with batteries beyond a bit for handling transient peaks. I guess what it comes to down for me is that the hybird as you described, while it has advantages over pure ICE, it's sorta the worst of both worlds - all the moving parts, all the complexity, the fire risk from both li-ion AND gasoline, more expensive (since two drivetrains, essentially). A constant RPM motor for an extended period isn't a super enjoyable sound, either.

sjm-lbm 3y ago
> If the engine is able to always operate at peak efficiency, there is little reason to bother with batteries beyond a bit for handling transient peaks. My thinking here is that most of these theoretical cars would spend a good part of their life only operating on battery power - basically, all of the home-to-work-to-supermarket-to-home trips would be pure electric in my mind. So much so that I've wondered if the ECU would need to occasionally run the ICE for a bit just to make sure it doesn't ever spend so much time without being turned on that entirely different problems arise. > it's sorta the worst of both worlds I get this. This idea is very much the best of both worlds/worst of both worlds depending on your point of view. > more expensive (since two drivetrains, essentially) I'm not sure about this. I think the right comparison here is to imagine a battery that has (say) 25% of the range of a Model 3 battery, but is (say) 30 or 35% of the cost. Based on EV battery replacement cost, could you buy a cheap 3-cyl ICE engine and generator for that? Intuitively this feels possible, though I'll admit I don't have access to the data to be able to say, for sure how these costs would compare at scale. > A constant RPM motor for an extended period isn't a super enjoyable sound, either. The sound should be similar to the sound a pure ICE car makes on the freeway when on cruse at a constant speed and not changing gear. Yeah, you'd need to tune the exhaust to make sure the sound is pleasing, but this feels like a solvable problem also. (As an aside, sorry if it feels like I'm hassling you. I'm honestly not, this is just an idea that has lived in the back of my brain for a bit and I'm enjoying the discussion.)
- TylerE 3y ago
  An ICE places a lot more constraints on design and manufacter...since it has to be behind a firewall, it's large, it has all kinds of fluids that need routing out... it's a nightmare. For comparison a typical EV battery is just a bunch of bricks inside the skateboard base.