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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

#271

Post by jweir »

AdamJacobMuller wrote: post #183
codeismath wrote: post #164

Earlier quoted context omitted.

Years ago I visited the Seneca Pumped Storage Generating Station [0] reservoir in person. It's a massive man-made lake on the top of a small mountain in Pennsylvania, USA. They pump water up to it at night (when there is excess energy in the power grid), and let the water out in the day when the demand for energy is high (turning some turbines on its way down). Prior to visiting I had an intellectual understanding of…

> one BIG BATTERY > The power plant, rated at 451 MW That's a damn big battery. I love pumped storage, too bad it's not used more.

Bah - Bath County can eat Seneca for breakfast and again for lunch and for dinner and then some. Max storage is 24000 MWh and can generate up to 3 GW

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

#272

Post by [deleted] »

ryanmarsh wrote: post #245
deadbunny wrote: post #173

Earlier quoted context omitted.

I got pulled over for this. I was driving home from a friend's at about 2am so nothing but clear roads, it was on about a 10 mile stretch of dual caradgeways with a few roundabouts along the way. At the 3rd roundabout I got the flashing lights and dutifully pulled over. Turns out they pulled me over because they thought my break lights were out. After a quick demonstration of my fully working break lights and a quick…

I do wish the Tesla would turn on the brake lights when slowing down at a certain rate (due to regenerative braking). I've nearly been rear-ended several times by cars that didn't expect me to "coast" that slowly or, conversely, slow down that fast without brake lights.

[deleted]

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

#273

Post by dahfizz »

elihu wrote: post #120

This seems like an interesting solution to the "what to do if my battery runs out in the middle of nowhere" problem. Normally, you'd either have to have to call a tow truck or have someone with a generator come along and recharge. However, towing for awhile (probably at much less than 70 mph for safety reasons) to recharge the battery enough to get to the next town is something that could presumably be done by just a…

> 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.

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

#274

Post by beerandt »

dahfizz wrote: post #263
FridayoLeary wrote: post #78

Earlier quoted context omitted.

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.

Literally destroying a mountainous environment is not clean energy.

But endless fields of solar panels and wind turbines is?

That seems like a somewhat arbitrary, fine line to walk.

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

#275

Post by unknown_error »

polishdude20 wrote: post #204
hourislate wrote: post #51

Earlier quoted context omitted.

This scenario is a little different than a car but a Swiss company is experimenting with a Komatsu Dump Truck that basically recharges its battery using regen braking on it's trip down so it has enough power for the trip up. It actually generates a surplus of an extra 10kwh because the truck is carrying a full load down. https://phys.org/news/2017-09-e-dumper-world-largest-electri...

What if you did this with passengers instead of a truck load of rocks? Carry passengers down a mountain, go up the mountain with an empty tesla.

I don't think the passengers would appreciate getting back up via plate tectonics.

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

#276

Post by ajross »

TylerE wrote: post #188
danboarder wrote: post #63

So he was getting supercharger speeds (50% battery in about a half hour) which is awesome! The Tesla has its own built in "supercharger" if you can find an alternative way to power it. My idea then is this - could a dyno be modified to be powered and function as competitive to a Tesla supercharger? Basically towing it in-place. It would be rad to see this work! I could imagine connecting it to a geared waterwheel for…

No, it quite explicitly states this is "fast" (e.g. home) charging and NOT even v1 supercharger speeds. "putting back electricity into the batter at a rate of 65 kW - not quite Supercharger speeds, not even V1 or V2 Superchargers that could muster up to 150 kW, but still pretty decent."

There are no home chargers that can supply 65 kW to anything. That's 270A of 240VAC current (which per most codes would need to be on a 340A circuit), where even large homes have a 200A circuit from the utility for the entire building. Home charging is AC charging, and peaks out around 48A/11kW.

The term "fast charging" refers to DC chargers that skip the transformer in the car (which is sized only for 11 kW or so) and do it in the charger device, supplying high voltage DC directly to the battery. And this gets into the dozens and hundreds of kW. Tesla's early superchargers were 75 kW, most CHAdeMO in the US is 50 kW, etc...

It's faster than some "fast chargers", yeah.

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

#277

Post by uncoder0 »

throwaway0a5e wrote: post #233
SomeHacker44 wrote: post #190

Earlier quoted context omitted.

GP almost certainly meant losses in the transfer from mechanical energy to chemical energy by way of the cars motors being used as generators, then charging the batteries.

Don't forget the double loss from sending the rotational energy to the ground and back.

Unsprung mass always surprises.

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

#278

Post by mr_toad »

rightbyte wrote: post #157
wazoox wrote: post #61

Earlier quoted context omitted.

I don't think so. Most vehicles have virtually no braking power with the engine off. It's definitely completely forbidden in France to tow with a rope, and I'm pretty sure this applies to all or at least most of UE too. In Germany, even tow dollies are forbidden.

> Most vehicles have virtually no braking power with the engine off You just need to press the brakes harder. Like 3 times harder, not 30. If you park in a slope and turn the engine off you can try braking after pumping the vacuum out - it works just fine.

If you’ve always used power assisted brakes and you’re not expecting to have to press really hard on the brakes it could easily lead you to rear end the car towing you if it stops suddenly. Also, without power assisted steering, modern cars are surprisingly difficult to control.

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

#279

Post by Matheus28 »

gpm wrote: post #219
dcanelhas wrote: post #105

They would clearly have been better off putting a diesel generator on a trailer behind the tesla, for fuel efficiency. 4 gal in 20 minutes the video said? That's about a 160kW generator https://www.hardydiesel.com/resources/diesel-generator-fuel-... I wonder how diesel generator + tesla compares to an actual diesel car.

Can you charge a tesla through the charging port while driving it?

No. It needs to be in park.
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