One thing that always puzzled me was how the gas engines in hybrids were so efficient. Technology Connections has a great video explainer: <a href="https://www.youtube.com/watch?v=KnUFH5GX_fI" rel="nofollow">https://www.youtube.com/watch?v=KnUFH5GX_fI
tl;dw: constant RPM and a weird stroke geometry where the power stroke is longer than the other strokes to extract more energy from the expanding gasses.
I'm surprised there isn't more effort to create hybrids in reverse--an electric car with optional gas generator. The gas generator could run at constant speed, never changing RMP, while the battery handles constant changes in acceleration. The idea is not mine. I've heard about it in China
There’s a lot of good replies here but I’ll add mine too:
The simples reason is this. What you’re describing is having a gas motor spin a thing (the generator) -> charge battery -> discharge battery -> spin a thing (the wheels) to make car go. Each of those steps has efficiency losses.
That’s why most hybrids are parallel hybrids, where both the gas engine and the battery+motors can spin the wheels more or less directly, even at the same time.
you still basically get the engine spinning at a more constant rpm, and the battery kicks in for acceleration (and charges on deceleration), and now highway cruising doesn’t have any lossy conversion steps, while acceleration and braking uses the advantages of the electric drive chain.
gcanyon · · focus · HN ↗
tl;dw: constant RPM and a weird stroke geometry where the power stroke is longer than the other strokes to extract more energy from the expanding gasses.
jostmey · · focus · HN ↗
jedbrooke · · focus · HN ↗
The simples reason is this. What you’re describing is having a gas motor spin a thing (the generator) -> charge battery -> discharge battery -> spin a thing (the wheels) to make car go. Each of those steps has efficiency losses.
That’s why most hybrids are parallel hybrids, where both the gas engine and the battery+motors can spin the wheels more or less directly, even at the same time.
you still basically get the engine spinning at a more constant rpm, and the battery kicks in for acceleration (and charges on deceleration), and now highway cruising doesn’t have any lossy conversion steps, while acceleration and braking uses the advantages of the electric drive chain.