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A comment on The Case Against More Ethanol (2016). Parent comment

Re:The Case Against More Ethanol (2016) by snarf21 on Monday November 02, 2020 @12:37PM (#24970729)
Does anyone have data on if we could build a small ICE that is strictly a generator? I know one issue is variable power needs but if there are say two banks of batteries and the one is running constantly at a fixed rate as more of a slow charge and the other is currently handling demand, would that work? Assuming that the banks could switch as one gets depleted and it begins charging.
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Re:The Case Against More Ethanol (2016) by jfk13 on Monday November 02, 2020 @01:09PM (#24971075)
Sounds like you want a diesel-electric locomotive. Or a smaller version of one, maybe.

https://en.wikipedia.org/wiki/Diesel_locomotive#Diesel–elect...

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Re:The Case Against More Ethanol (2016) by GloriousKoji on Monday November 02, 2020 @12:56PM (#24970931)
Sounds like a series hybrid card to me. Off the top of my head I can only think of two cars with this design, the Chevy Volt and BMW i3 with range extender.
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Re:The Case Against More Ethanol (2016) by dragonwriter on Monday November 02, 2020 @12:58PM (#24970944)
> Does anyone have data on if we could build a small ICE that is strictly a generator?

Obviously, ICEs that are strictly used to crank generators are common.

If you mean “is there data on whether that works in what is otherwise a battery-electric car”, that's called a series hybrid, and there are several production examples, including the Chevy Volt.

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Re:The Case Against More Ethanol (2016) by gwbas1c on Monday November 02, 2020 @01:38PM (#24971444)
Yes: They are called "portable generators."

Long answer: Before WWII, there were luxury cars built this way. Manual transmissions were much harder to drive, so some luxury cars used a generator/motor pair as an automatic transmission.

WWII needs for copper drove them out of the market; and they never came back because it was simpler to just mate an oversized engine with a horrible automatic.

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Re:The Case Against More Ethanol (2016) by kayodelycaon on Monday November 02, 2020 @12:52PM (#24970896)
Why have the ICE be strictly a generator? If you have one, it’s far more efficient to use it to drive the wheels. Toyota’s Prius effectively does this using batteries during periods when using the ICE would be inefficient. (Generally, it isn’t perfect.)
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Re:The Case Against More Ethanol (2016) by VBprogrammer on Monday November 02, 2020 @01:32PM (#24971385)
> If you have one, it’s far more efficient to use it to drive the wheels.

I don't think this is as cut and dried as you think. Generators are ~90% efficient. Gearboxes and differentials aren't 100% efficient either. If you are already carrying enough motor to propel you without an engine then you can size the ICE closer to average load than peak load potentially getting back a bit of efficiency.

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Re:The Case Against More Ethanol (2016) by gbrown on Monday November 02, 2020 @01:01PM (#24970986)
The idea is that you can tune/simplify the motor to run at one or a few RPMs, and also simplify the drive train.
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Re:The Case Against More Ethanol (2016) by snarf21 on Monday November 02, 2020 @01:35PM (#24971417)
Right, the intent would be to run at only a single very efficient RPM for the purpose of generation with no directional power transitions.
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