Arthur T Knackerbracket has processed the following story:
Tesla is warning users about a popular "charging hack" that can allegedly result in shorter wait times at select Supercharger stations. The trick, which has been circulating within the Tesla community for at least a few years now, involves wrapping a damp towel around a Supercharger handle when charging. The idea is that the wet rag acts as a cooling agent, tricking temperature sensors inside the handle into thinking the system is running cooler than it actually is.
Some claim the hack can increase the charging rate, especially on hot summer days, resulting in a faster charge and less waiting around. Now, Tesla has issued official guidance on the matter.
According to the official Tesla Charging account on X, placing a wet cloth on a Supercharger handle does not increase its charging rate. In does, however, interfere with the system's temperature monitors and could lead to overheating or damage. Tesla advises against the towel trick to help ensure their systems can operate correctly.
[...] Inside EVs points to several instances that seem to refute Tesla's claim that the trick does not work, at least with older V2 Supercharging systems. One Tesla user put a damp cloth over the charging handle on a V2 Supercharger, which increased the charging rate from 60 kilowatts to 95 kW on a hot day. Another user plugged in at two percent stage of charge and reached 147 kW before thermal throttling kicked in at 34 percent and slowed the rate down to 58 kW. Applying a wet rag reportedly drove the charging rate up to 119 kW.
V3 and newer Superchargers utilize active cooling. According to Inside EV, the towel trick does not really help at all on these systems unless you are charging a Cybertruck.
Tesla owners would probably be best served to take the company's advice and not fool with the trick. Saving an extra few minutes simply is not worth the risk of damaging your vehicle or Tesla's equipment.
(Score: 3, Insightful) by Anonymous Coward on Tuesday July 30 2024, @10:22PM (2 children)
Evap cooling does work on hot dry days, but around here (steamy in NE USA this week) not so much--the wet towel will warm up and at 80%+ relative humidity, it's going to stay wet.
This whole idea of fast charging is kind of dumb anyway--it shortens the life of the currently available batteries. Just accept that long trips with multiple charging stops are either a bad idea at this stage of BEV development, or plan on a leisurely trip with extended charging stops.
(Score: 5, Interesting) by darkfeline on Wednesday July 31 2024, @08:15AM (1 child)
But EV is going to get even less appealing if we can't maintain the agenda that it is superior to ICE in every way.
46% of EV owners in the US (and 29% globally) want to go back to ICE.
https://executivedigest.sapo.pt/wp-content/uploads/2024/06/Mobility-Consumer-Pulse-2024_Overview.pdf [executivedigest.sapo.pt]
If we lose fast charging, those stats are only going in one direction.
Join the SDF Public Access UNIX System today!
(Score: 4, Insightful) by mcgrew on Wednesday July 31 2024, @01:36PM
That's an incredibly bad website.
"Of electric vehicle owners consider to
switch back to a traditional..."
Note the propagandistic key words. Like the coffee cup my daughter bought me says, "nice story, now show me the data." Were the questions asked in the same way the "data" were presented?
It's propaganda, not a study. [mcgrew.info]
It is a disgrace that the richest nation in the world has hunger and homelessness.
(Score: 4, Touché) by Thexalon on Tuesday July 30 2024, @10:51PM (2 children)
I mean, you wouldn't want to do anything super-dangerous like, I dunno, parking it in the rain [cbsnews.com].
"Think of how stupid the average person is. Then realize half of 'em are stupider than that." - George Carlin
(Score: 2, Informative) by mcgrew on Wednesday July 31 2024, @01:43PM (1 child)
That's what they get for buying a car from a Nazi. And what does a rusting body have to do with its method of propulsion? Except the fact that it's a shitty car altogether?
My Hyundai EV (no more Hyundais, 3 recalls in six months) has been parked in the driveway since I bought it last September (for you pedants, except of course when I was driving it), in the rain, snow, well-below freezing temperatures, blistering heat (illinois), and aside from recalls has been the best car I ever owned.
The problem isn't that it's an EV, the problem is that it's a Tesla.
It is a disgrace that the richest nation in the world has hunger and homelessness.
(Score: 0) by Anonymous Coward on Wednesday July 31 2024, @11:44PM
Inquiring minds want to hear more about your Hyundai BEV:
What were the recalls for?
Did your car show the symptoms, or just get recalled for good measure?
How long did the dealer keep your car to perform the updates?
Did they give you a loaner car (ICE or BEV)?
(Score: 3, Touché) by SomeGuy on Tuesday July 30 2024, @11:09PM (4 children)
Ah, the crazy uses people find for those towels.
Although, reading things like this makes me glad that my old gas guzzling roll-mobile only takes a couple of minutes to fill up at the pump. Ya know, you don't even have to go inside to pay in cash any more. Pay with credit card, or at some places perhaps even with a glorious almighty smart phone (Don't own one, I wouldn't know). You might be able to use a towel for that, but you would probably get in to trouble.
(Score: 2) by aafcac on Tuesday July 30 2024, @11:27PM
You're supposed to be doing other things while the car is charging. So, while at work or on the restaurant. It's mostly road trips where it might be an issue.
(Score: 5, Funny) by mhajicek on Wednesday July 31 2024, @12:09AM (1 child)
It's a tough universe. You'd better know where your towel is.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 3, Touché) by aafcac on Wednesday July 31 2024, @12:19AM
And thanks to this technique I know it's been stolen by the gentlemen that stole the copper charge cable.
(Score: 2, Interesting) by mcgrew on Wednesday July 31 2024, @01:54PM
How often do most people travel more than a two hundred mile round trip? The gas station was the one reason I bought an EV, if gas stations were still full service I would never have known about all the other advantages.
I always hated pumping gas, especially in the winter. When I first started driving in 1968 I didn't have to, self-service was in the future. Now, I just plug my car into the 110v outlet on the outside of my house. Maybe thirty seconds. No freezing in the snow while the attendant inside finishes selling that lottery ticket and turns the pump on.
You don't have to babysit an EV.
A couple of minutes? At a big busy gas station with only one one register jockey it's taken me over twenty minutes at times.
I live on a busy street. I wish you gasoline people would keep your stinky cars in tune!
It is a disgrace that the richest nation in the world has hunger and homelessness.
(Score: 1, Insightful) by Anonymous Coward on Wednesday July 31 2024, @01:34AM (3 children)
AFAIK this wet towel trick should only convince the charger that the handle part is not getting too hot[1] (which would be true). If the charger is assuming more than that and going out of spec then it could be dangerous in other scenarios e.g. where the handle gets cooled by the weather while the vehicle isn't that cool.
[1] The handle getting too hot could be a safety issue for people trying to touch or use the handle. So presumably you do really want to ensure the handle doesn't get too hot. But if the towel succeeds and doesn't short stuff etc then there where's the problem (other than maybe the significant increase in electrical consumption?).
(Score: 3, Insightful) by Anonymous Coward on Wednesday July 31 2024, @01:44AM (2 children)
Just 'cause you keep the outside cold with evaporative cooling doesn't mean that the cables and other bits inside the handle are cool enough. Since the (plastic?) handle is somewhat of a thermal insulator, the outside could be cool enough to hold...while inside is much hotter.
I'll make a WAG and suggest that the plastic that insulates the connection pins & sockets is the critical bit. A bit of a high resistance at any of the power connections is going to get hot. If that melts the insulation the connector is ruined (best case) or shorts (you don't want to be around with that kind of energy flow).
(Score: 2) by stratified cake on Wednesday July 31 2024, @06:07AM (1 child)
As far as I understand it, it's purely a liability thing. Other temperature sensors monitor spots all along the flow of electricity and the battery of course.
The one in the handle is there to protect feeble humans from getting burnt.
Disclaimer: Based on statements by Tesla, any similarity to the truth entirely coincidental.
(Score: 0) by Anonymous Coward on Wednesday July 31 2024, @08:47AM
e.g. if the temperature sensor not too hot because the handle surface is cold, then the cable has to be not too hot either.
It's like an oven temperature sensor in the oven, and you put the cold towel on the oven door handle to cool it down. Sure that might affect the temperature sensor in the oven a bit, but it's still going to be pretty close to the oven temperature.
But if you have a temperature sensor on the oven door handle, someone is doing it badly wrong if that sensor is supposed to measure the oven temperature.
(Score: 3, Insightful) by Runaway1956 on Wednesday July 31 2024, @01:53AM (4 children)
If you know how to trick a sensor, the computer that runs the machinery is going to act according to the sensor's input. There's a temperature sensor (probably a bimetal thermosatat) in the plug? Yeah, evaporative cooling is going to convince the computer that the plug is a degree or ten below what it should be. That may be important, but the more important reading is the temperature of the batteries. I certainly hope the computer is monitoring THAT temperature, in multiple places.
But, yeah, as a maintenance guy, I bypassed sensors often while troubleshooting machinery. And, I often wrote up technicians who bypassed sensors. And, I would damn sure write up an operator for doing so. All those sensors serve a purpose, and some idiot bypassing a sensor while the machine is in operation can cause all sorts of problems. That Tesla is your property, do whatever you want to do. But don't expect sympathy from me if you burn up your nice, expensive Tesla by tricking a safety sensor.
“I have become friends with many school shooters” - Tampon Tim Walz
(Score: 3, Interesting) by pTamok on Wednesday July 31 2024, @07:51AM (3 children)
Many humans regard it as acceptable to take a risk of major damage to gain a short-term advantage. In a lot of situations it is a winning strategy. If major damage happens, it is often dismissed as 'just bad luck'.
Cutting corners allows you to beat the competition that doesn't cut corners - most of the time. Just occasionally you get a spectacular wipe-out.
From a technical point of view, I wonder if a solution would be to have two sensors at different distances away from the source of heat, and measure the absolute value of the one closest to the heat source and the difference between that and the outer one. From that, you can extrapolate the temperature at the heat-source, and if the delta gets too high, it indicates the source temperature is too high, and therefore slow down the charging. Differentially cooling the outer sensor would slow things down. Heating the outer sensor up to reduce the delta won't improve matters either, because you would be measuring the absolute value of the inner sensor.
(Score: 2) by looorg on Wednesday July 31 2024, @09:36AM (2 children)
Wouldn't they just get a bigger towel then? To cover both sensors. It seems like somewhat of a bad idea to mix wet (or moist) towels with electricity. But then it's not my car. If the sensor senses wet shouldn't it assume it's raining instead of just being cold. Or perhaps it should at least check with its weather app to see what the weather is actually like.
That said if this is a thing, which it apparently is even tho I had never heard of it before, I'm surprised someone has not come up with some kind of device to make it even colder. Perhaps something you keep in the freezer and then just attach to the handle when you need super charging. How about just running liquid nitro along the pole. Then it's real cold. Super charge indeed. And frost damage.
(Score: 1) by pTamok on Wednesday July 31 2024, @12:29PM (1 child)
I see I did not make myself clear. The heat source is the copper wires (or possible the mechanical connection between the copper wires and the connector pins, or even the interface between the pins and the socket receptacles). A thermometer is needed as close as possible to the copper, then one 'further out', closer to the surface of the cable (or closer to the surface of the handle) - not two thermometers at different distances along the cable. So a bigger towel doesn't help. The aim is to measure the temperature gradient from the core of the cable (or handle) to the outside, and prevent it getting too steep.
(Score: 0) by Anonymous Coward on Wednesday July 31 2024, @12:59PM
I got your meaning the first time (two temp sensors, at different distances from the heat source).
But I think this violates your other comment:
> Cutting corners allows you to beat the competition that doesn't cut corners - most of the time. Just occasionally you get a spectacular wipe-out.
Seems likely that Tesla cut this corner (only one sensor) to get their charging connector on the market at a low cost. Certainly Tesla has had some other "spectacular wipe-outs".
(Score: 2) by Nuke on Wednesday July 31 2024, @12:57PM (2 children)
Apart from the heat issue, what voltage do these chargers run at? Will you get electrocuted via a wet towel before your battery explodes?
(Score: 1, Redundant) by mcgrew on Wednesday July 31 2024, @02:02PM
I've read that fast chargers are 400 volts, but voltage alone can't kill you. The higher the voltage the faster it will charge, but one amp at ten volts will kill you. In an American house you have 110-120 volts at unlimited (except for the circuit breakers' rating). The wires from pole to pole are 700 volts, the tower cables are 90,000.
My car is waterproof, and I expect they all are. You're not going to be electrocuted.
Did you know that when Volta invented the electrical battery, there was no known use for electricity?
It is a disgrace that the richest nation in the world has hunger and homelessness.
(Score: 3, Informative) by dwilson98052 on Thursday August 01 2024, @08:28AM
Highly unlikely you would ever get shocked.
These are made to use in all weather conditions including rain.
They have GFCI protection and sense the connection to make sure things are ok before they ever start charging.
If there are any anomalies the charger won't start or will stop if it's already charging.
There is always slim the possibility that all of the built in safeties could fail, but you would still have to get the electricity to jump a pretty long path to get to you... so you would have to have all the safeties fail AND have a damaged charger.... or be charging while doused in saltwater or battery acid or some other electrolyte.
They're really quite safe.......... most of the time. ;-)
(Score: 2) by Freeman on Wednesday July 31 2024, @02:03PM
The indispensable towel, though perhaps best not used to bypass safety limits.
https://en.wikipedia.org/wiki/Towel_Day [wikipedia.org]
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"