Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

insideevs.com

Post reply on HN
Print view View original

341–350 of 399 posts

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

#341

Post by alliao »

cartoonworld wrote: post #194
extrapickles wrote: post #177

Earlier quoted context omitted.

When correctly muffled, engine breaking is not really any noisier than the engine operating normally. Truckers will sometimes install a valve to bypass the muffler, so they can let someone know that they just cut them off, and that they should try moving out of the way.

Engine braking is definitely always much louder than regular braking. Don't piss off your neighbors. The bypass valve on semi's you're referring to is not the exhaust. The huge BRAAAAAAAP that you hear coming from trucks when someone cuts them off aren't an exhaust bypass valve, its them slamming on their brakes to avoid a tragic 20-car pileup. It is a release of the compressed air-fuel mixture momentarily before com…

do you know how does those volvo semis stop on a dime? are there some sort of destructive braking mechanism to perform emergency brake?

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

#342

Post by kzrdude »

FridayoLeary wrote: post #78
ols wrote: post #56

The most spectacular example of regenerative braking are trains that are used in Scandinavia, heavily loaded with iron ore that is transported to the coast: "In Scandinavia the Kiruna to Narvik electrified railway carries iron ore on the steeply-graded route from the mines in Kiruna, in the north of Sweden, down to the port of Narvik in Norway to this day. The rail cars are full of thousands of tons of iron ore on th…

The heavy iron ore is essentially a large battery storing gravitational energy. In a way it's just another natural energy source. Maybe in the future clean power can be generated from pulling down mountains.

The iron ore was pulled up from the ground, so "some" energy is used there, to lift it into the trains. Now the mine is not quite as deep as ocean level, so there is still a net potential energy gain (you could say).

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

#343

Post by fho »

jgjot-singh wrote: post #338
bodyfour wrote: post #146

Earlier quoted context omitted.

It's interesting as a thought, but I don't think it's likely to be large-scale practical. Suppose you wanted to run a normal electric train up a mountain. It would certainly take a decent amount of power but not so much that it would be a big challenge for a city-scale power grid. So far you're not yet talking the scale of power where storing it would really be interesting to a grid. One option to store more power wo…

Perhaps the trains could partly be passenger trains, costing amusemant park rates. Then collected money could eventually pay off the cost of construction, and eventually maybe even offset the maintenance cost. If nothing else, it would certainly boast the advantage of being more fun than water storage.

Ideally have the transportees walk up the hill by themselves, summer sledding style. That way you are by some strange definition guaranteed to be net positive ;-)

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

#344

Post by canadianfella »

iancmceachern wrote: post #313
rootusrootus wrote: post #253

Earlier quoted context omitted.

I'm surprised it was that good. I get 8 MPG from my F250 when towing a travel trailer that doesn't have the brakes engaged.

I too exist where the vent diagrams of HN reader and F250/travel trailer owners intersect.

Vent?

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

#345

Post by fho »

asdff wrote: post #127
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.

You can get this sort of benefit with a gas car with a manual transmission too. Engine braking uses no gas, its just your wheels turning your pistons and the friction from all of that slows the car down. Most of the time I only hit the brakes to go from 5mph-0mph in a manual car thanks to this.

I recently changed from a 20 yo diesel to a 10 yo gas/benzine car ... on the old car "motor braking" got me reliable from 100 km/h (over land) to 50 km/h (city) speeds ... the "new" car apparently has less losses and motor braking doesn't seem to do me any good anymore :-/

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

#348

Post by dahfizz »

Gustomaximus wrote: post #305
dahfizz wrote: post #273

Earlier quoted context omitted.

> However, towing for awhile ... is something that could presumably be done by just about any passing car A Tesla model 3 weighs over 4000 pounds. A base model Toyota Tacoma isn't even rated to tow that weight, there's no way any passing sedan could. Now remember that for regenerative _braking_ to work, the tesla's brakes have been on! Definitely not something any passing car can handle.

> A base model Toyota Tacoma isn't even rated to tow that weight Isnt this rating more about supporting and breaking force for the combined vehicle and load weight. My understanding in this case tow means 'pull the vehicle' vs carry the front weight. So I think even a smaller car would be fine to pull a Tesla.

Being able to safely break is part of the towing test, as well as being able to haul the load up hill at highway speed.

The point is that an average sedan absolutely does not have the power to tow 4,000 pounds, let alone 4,000 pounds with it's breaks on.

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

#349

Post by jmiserez »

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

Or just hop on a car train (while staying in your car). It's super relaxing e.g through a tunnel, you just drive on and then off. See https://en.wikipedia.org/wiki/Car_shuttle_train for some examples.

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

#350

Post by dmayle »

jtbayly wrote: post #180
dmayle wrote: post #47

Earlier quoted context omitted.

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.

I question your memory. Lol.

Fair enough... Memory is definitely fallible. In my memory, the car is blue, and what I remember seeing is someone pulling the poles off of the line, but just like we've seen with neural networks, maybe my brain is backfilling the events after having read the story.
Post reply on HN