Obviously a fast tow will generate a faster charge, but does the total amount of energy imparted depend only on distance? Or maybe it actually falls slightly at higher speeds? (The latter is my intuition.)
Towing a Tesla at 70 MPH replenishes battery at fast charger rates
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Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#42We have trains in chicago that reach whiskers up to charging lines above them. Same as the trolley systems in San Francisco. What if every major city to city freeway stretch had these in a lane for electric vehicles?
I don't know whether or not it is legal, but I have seen an electric car with tram whiskers before. I think I saw it in San Francisco, and I think it was a Prius. Some quick Googling fails to turn it up, though. EDIT Found a link: https://thebolditalic.com/hacked-prius-running-on-muni-power...
That is awesome but the article's date is April 1st 2014.
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#43Earlier quoted context omitted.
Show HN: lapetitejort goes hiking, discovers perpetual motion
That would be a neat test. Find a steep hill, preferably as straight as possible, and test how many times an electric car can traverse it before running out of batteries. Would the distance traveled exceed that on a flat road with no generation? By how much? I'm sure someone in San Fran has already tested this.
My intuition would say you'd never have longer range driving up and down a hill compared to driving flat in a straight line (and never braking).
I would imagine that at best, you could maybe match the range. If there's any scenario where going up and down a hill would yield more range than driving flat, I'd be very interested in how/why.
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#44Earlier quoted context omitted.
Show HN: lapetitejort goes hiking, discovers perpetual motion
That would be a neat test. Find a steep hill, preferably as straight as possible, and test how many times an electric car can traverse it before running out of batteries. Would the distance traveled exceed that on a flat road with no generation? By how much? I'm sure someone in San Fran has already tested this.
In theory they would be identical, but in practice a flat road would be better. There are more real world inefficiencies with going up and down a hill.
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#45It seems like the tire wear wouldn't be worth it. You're pulling the tires at almost 100 horsepower of energy transfer. Sure, neat for a video gag though.
It’s likely fine, 65 kW is only ~85 HP. Simply maintaining highway speeds is ~25HP, so as far as the tire is concerned it’s the equivalent of mild acceleration or breaking. The regenerative breaking system is likely designed for long mountain roads, so it might overheat but probably not.
65 kW is a little over 87 horsepower (parent previously claimed ~80 HP, now edited to 85).
To get 65 kW into the battery, you have mechanical and electrical conversion losses on top of that. The tires are seeing pretty close to 100HP.
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#46Earlier quoted context omitted.
Show HN: lapetitejort goes hiking, discovers perpetual motion
+3 miles hopefully didn’t include the energy spent going up, or the law of energy conservation would have been broken.
I think the wind at his back is key here. His car was acting like a wind turbine
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#47Earlier quoted context omitted.
I don't know whether or not it is legal, but I have seen an electric car with tram whiskers before. I think I saw it in San Francisco, and I think it was a Prius. Some quick Googling fails to turn it up, though. EDIT Found a link: https://thebolditalic.com/hacked-prius-running-on-muni-power...
That is awesome but the article's date is April 1st 2014.
Be that as it may, I saw the actual car before I ever saw the article. Maybe it was him, maybe the article is fake, but it inspired someone to try it for real. Either way, I've seen a real life car doing this.
EDIT I've found confirmation that the article is an April Fool's joke. I still, however, have seen a car doing this (or at least attempting to do this) on the streets of San Francisco.
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#48Earlier quoted context omitted.
Show HN: lapetitejort goes hiking, discovers perpetual motion
That would be a neat test. Find a steep hill, preferably as straight as possible, and test how many times an electric car can traverse it before running out of batteries. Would the distance traveled exceed that on a flat road with no generation? By how much? I'm sure someone in San Fran has already tested this.
Would the distance traveled exceed that on a flat road with no generation?
No. Climbing the hill the car uses extra energy (compared to a flat road) because its fighting gravity. On the way back down the hill regen will recover some of that gravity-fighting energy but nowhere near all of it.
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#49I wonder if we'll ever have recharging drones that sense your car is running low, pull ahead of you, and just start towing your car for a ways so you don't even have to stop.
Or you could have dyno-based chargers that work like automated car washes. Pull in to a stall, guided onto the drums, put in gear, go for a coffee.
Cons:
- Less efficient than using an actual electrical cable.
- Requires larger infrastructure space.
Pros:
- Could work with any brand that has regenerative braking.
- Could be adapted into existing automated car washes as a premium feature.
Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates
#50Earlier quoted context omitted.
That would be a neat test. Find a steep hill, preferably as straight as possible, and test how many times an electric car can traverse it before running out of batteries. Would the distance traveled exceed that on a flat road with no generation? By how much? I'm sure someone in San Fran has already tested this.
My intuition would say you'd never have longer range driving up and down a hill compared to driving flat in a straight line (and never braking). I would imagine that at best, you could maybe match the range. If there's any scenario where going up and down a hill would yield more range than driving flat, I'd be very interested in how/why.
Yeah, rethinking it, assuming you start and end at the same spot, the milage at the beginning is the max you can achieve, full stop. Simple conservation of energy. So the question becomes, how many miles do you lose at the end?