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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

#31

Post by wazoox »

bellyfullofbac wrote: post #23
sokoloff wrote: post #6

It 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.

Hah, don't try it in Europe either, max towing speed in Europe is 40km/h or 25mph. I guess a tow truck with a bed that has a rolling road would be an idea, prop up the car so the weight of the car isn't actually exerting force that makes the wheels harder to turn/cause extra wear. Or the "rolling road" can be replaced be a contraption that attaches to the wheels by e.g. its rims, and spins it.

Plus in Europe it's forbidden to tow with a rope like he does. You must use a rigid link, like a bar or a tube.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#32

Post by seanmcdirmid »

unknown_error wrote: post #16
lapetitejort wrote: post #12

Regenerative braking is so neat. I drove up a steep windy road to go on a hike with my plugin hybrid. On the way down I tried to let gravity do all of the acceleration and regenerative braking do all of the deceleration. At the bottom of the hill I had racked up +3 miles in total. Another fringe benefit is that brake pads wear out slower and produce less pollution.

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.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#33

Post by Retric »

sokoloff wrote: post #6

It 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.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#34

Post by SketchySeaBeast »

dronechariots wrote: post #9
devoutsalsa wrote: post #5

I 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.

At that point, why not just have drone chariots that pull you the whole way

... And we've reinvented pod-racing.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#35

Post by Retric »

ErikVandeWater wrote: post #27
Retric wrote: post #20

Earlier quoted context omitted.

And even better just embed some wires in the road and charge everyone at highway speeds. Either ground-level power supply through conductive rails or inductive coils both work with different tradeoffs. https://en.wikipedia.org/wiki/Electric_road

> Just embed some wires in the road... No offense but that is the most loaded phrase I've heard this week. That would be a major overhaul of both roads and electric car designs.

Several different systems are all at demonstration phases. EX: https://www.theguardian.com/environment/2018/apr/12/worlds-f...

I suspect the hard part is getting every car manufacturer to agree to the same system not designing something that works.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#36

Post by raverbashing »

wazoox wrote: post #31
bellyfullofbac wrote: post #23

Earlier quoted context omitted.

Hah, don't try it in Europe either, max towing speed in Europe is 40km/h or 25mph. I guess a tow truck with a bed that has a rolling road would be an idea, prop up the car so the weight of the car isn't actually exerting force that makes the wheels harder to turn/cause extra wear. Or the "rolling road" can be replaced be a contraption that attaches to the wheels by e.g. its rims, and spins it.

Plus in Europe it's forbidden to tow with a rope like he does. You must use a rigid link, like a bar or a tube.

Not necessarily forbidden, but there's a good reason for not towing with a rope. Especially at 70MPH (which is 112 kph)

Though towing a Tesla with regerative braking is the best case. You definitely wouldn't want to tow anything that can't brake or steer with a rope.

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#37

Post by muststopmyths »

hughrr wrote: post #28
Simulacra wrote: post #2

What if they had a Tesla merry-go-round where instead of charging your Tesla, you connected it to this giant horizontal ferris wheel that spun it around and charged the battery? It could be wind powered!

I had a similar idea which involved a large amount of gerbils in a giant wheel. They can convert sunflower seeds (which are of course solar powered) into energy 24/7. Thanks to your stroke of genius instead of using a generator and charging your EV you can just put a wheel next to it and leave the Tesla on it now. I haven’t worked out what to do with half a ton of gerbil corpses, shit and sunflower seed shells yet th…

Biogas, obviously !

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#38

Post by ErikVandeWater »

pcarolan wrote: post #15

We 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?

Are all the cars going to reach up 13 feet in the air to the charging lines? That would be a very tough sell. Not to mention the increased danger of live power lines coming down in an accident.

Also, how would lane changing work? Do they have to decouple from one set of power lines and connect to another?

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#39

Post by toomuchtodo »

Retric wrote: post #33
sokoloff wrote: post #6

It 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.

Teslas will switch to friction brakes when regeneration limits (peak current or battery SOC) are exceeded. I’ve sustained constant 50kw regen while downhill through Appalachia passes, no issues, with the caveat that regen current is limited if the pack is cold until it approaches operating temperature (yellow dashed lines on the regen current display indicate your reduced regen capability).

Re: Towing a Tesla at 70 MPH replenishes battery at fast charger rates

#40

Post by efraim »

wazoox wrote: post #31
bellyfullofbac wrote: post #23

Earlier quoted context omitted.

Hah, don't try it in Europe either, max towing speed in Europe is 40km/h or 25mph. I guess a tow truck with a bed that has a rolling road would be an idea, prop up the car so the weight of the car isn't actually exerting force that makes the wheels harder to turn/cause extra wear. Or the "rolling road" can be replaced be a contraption that attaches to the wheels by e.g. its rims, and spins it.

Plus in Europe it's forbidden to tow with a rope like he does. You must use a rigid link, like a bar or a tube.

Not true, a rope is fine.
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