4 ms·
Maybe someone who knows more on the matter could help me understand the efficiency problem. Wouldn't it be more efficient for long trips to run a small generat
by geokon 4y ago
Maybe someone who knows more on the matter could help me understand the efficiency problem.
Wouldn't it be more efficient for long trips to run a small generator in the car that charged the batteries?
A car engine needs to deal with variable power/torque/etc. It's got transmissions and radiators and all sorts of extra complexities. A generator runs at one speed and is efficiently tuned to that one speed. If you suddenly need more power to accelerate then that would be provided by the batteries. Batteries are like >90% efficient. So going motor->battery->wheels seems like you wouldn't loose much even in the worse case of coasting on the highway at an ICE's optimal speed.
Generators are also generally simpler and smaller. You could envision one that you could pop into the frunk when you need extra range. It would continuously recharge your batteries as you drive - even before they're depleted. Even if it didn't recharge as fast as you were using up power - you'd still drastically increase your range. Forthermore you could leave it running overnight to charge your car if you're in some remote place with no charging stations
Literally nobody has done this - so there must be some reason I'm overlooking :)
- deleted 4y ago[deleted]
- endisneigh 4y ago> Wouldn't it be more efficient for long trips to run a small generator in the car that charged the batteries? See the Toyota Prius. This is already what is done.
- geokon 4y agoOh, it is in effect kinda similar. Though it does it through gearing https://en.wikipedia.org/wiki/Hybrid_Synergy_Drive https://en.wikipedia.org/wiki/Hybrid_Synergy_Drive Not quite motor->battery->wheels. I guess to have the generator be removeable you need a much smaller engine as well
- timbit42 4y agoI think the Chevy Volt is what you're talking about. You plug it in to charge and when the battery runs out, the engine runs to charge the battery so you can drive until the gasoline runs out. The engine isn't connected to the wheels at all. It only charges the battery as you drive.
- geokon 4y agoI didn't realize it was that separated. Would be cool if you could detach the engine entirely and leave it at home when you don't need it. Or buy the car without an engine and rent one when you want to do the annual roadtrip
- zb 4y agoAIUI the Hybrid Synergy Drive combines aspects of a series and parallel hybrid, for efficiency at both high and low speeds. I think this is the main reason that pure series hybrids are not more popular.
- zb 4y agoThis is called a series hybrid and there are lots of them on the market.
- geokon 4y agoYeah, I was wrong. Thanks for pointing it out https://en.wikipedia.org/wiki/Hybrid_vehicle_drivetrain#Series_hybrid https://en.wikipedia.org/wiki/Hybrid_vehicle_drivetrain#Seri...
- achow 4y ago> Literally nobody has done this Not entirely true. Diesel-Electric Locomotives though colloquially called 'Diesel trains' but they do what you are proposing. And this tech is from 1930s-40s. https://www.up.com/aboutup/special_trains/diesel-electric/index.htm https://www.up.com/aboutup/special_trains/diesel-electric/in...
- dagw 4y agoLiterally nobody has done this This is exactly what the Fisker Karma was doing 10-12ish years ago.