Model 3 Myths

[SammichLover]

I'm not sure if you're trolling or honestly misinformed,

Neither.

That's some serious projection on your part.

Heat most certainly comes out of the battery because it is not perfectly insulated (it's not even well insulated).

I mean WTF???? This has bearing on the discussion at hand? This is the worst kind of pedantry, misdirecting gibberish.

This is probably an attempt to show that less energy is available from cold battery.

It is because charge level is determined by voltage level, and the voltage level drops because of what I said.

If you hadn't cut High School Chemistry to go smoke outback of the gym you might know about this.

That's just a sampling from a quick scan of your post, on and on your nonsense goes.....

 

[Vegaforce]

Its funny how many of the myths posted here have started by the "man" himself: Elon.

I found this website funny and maybe somehow related to this thread: ElonMuskToday

My favorite myth: FSD will be available by the end of "this" year.

 

[camalaio]

I mean WTF???? This has bearing on the discussion at hand? This is the worst kind of pedantry, misdirecting gibberish.

Alternatively, perhaps it was my misunderstanding of your statement "[...] use the motor to circulate heat into the battery, but it never comes out of the battery [...]". No pedantry intended, perhaps just a common failing of interpreting text-only mediums incorrectly. Though I'm still not sure what else you may have meant by that?

It is because charge level is determined by voltage level, and the voltage level drops because of what I said.

If you hadn't cut High School Chemistry to go smoke outback of the gym you might know about this.

That's just a sampling from a quick scan of your post, on and on your nonsense goes.....

Charge level is a heck of a lot more complicated than voltage level, but it's a usable measure. However, a lot more than voltage sag causes reduced capacity in reduced temps. You can find a lot information that shows the actual amp-hour (Ah) capacity of the battery drops with temperature, which is independent of voltage. The voltage sag does also depend on the current draw; at rest the voltage sag is a lot less.

Also, no (optional) high school chemistry class I'm aware of teaches the incredibly complicated behaviour of lithium ion cells with respect to environmental factors. Not when I was in school and probably not now, and nor would it be relevant to Tesla's chemistry specifically. Happily, a lot of this information is free for us to find even outside of schools now for those that are interested in the topic.

 

[SammichLover]

Alternatively, perhaps it was my misunderstanding of your statement "[...] use the motor to circulate heat into the battery, but it never comes out of the battery [...]".

Yes, you brain farted and forgot about context, that being what you were claiming. The power to create the heat in the motor (that heat then getting circulated into the battery via the coolant loop) doesn't come out of the battery.

Your stuff was just tangental gibberish, if you'd taken a moment to consider (and intended to post in good faith) that should have been very clear.

Charge level is a heck of a lot more complicated than voltage level...

The way your Tesla detects it to report the charge level, nope. That's it. The BMS periodically calibrates what the voltage means, to translate that into percentage or miles, but that's over time and data gathered at various charge levels to work out the appropriate scaling factor. However it doesn't redo it in the moment.

Also, no (optional) high school chemistry class I'm aware of teaches the incredibly complicated behaviour of lithium ion cells with respect to environmental factors.

Sure. That's the point of reference to HS, this is just basic chemistry concepts. There's lots of more fine detail (like it being wet battery and so on) but the basic, "dumbed down" concept suffices here. It isn't limited to lithium batteries.

 

[camalaio]

Yes, you brain farted and forgot about context, that being what you were claiming. The power to create the heat in the motor (that heat then getting circulated into the battery via the coolant loop) doesn't come out of the battery.

Your stuff was just tangental gibberish, if you'd taken a moment to consider (and intended to post in good faith) that should be very clear.

Wait, where are you saying the power for heating comes from then?

If the context was as you say (what I was claiming: battery can be heated in the cold when unplugged), then it's not coming from the wall because it's not plugged into one. The battery is the only source of energy.

If it was your context (battery heating while charging), then power can still be taken from the battery for that task. A few people on here have confirmed that behaviour: power draw can exceed wall supply and end up discharging the battery slightly. In many cases it won't exceed wall power, but there are cases where it does (especially after it's done charging - if it's awake and in standby, it often disconnects from the charger). The thought that the car only ever takes power from the wall and not the battery when plugged in is yet another myth, actually.

For level 2 charging especially, I've personally seen it discharge the battery (for warming via motors) prior to charging. The behaviour is notably different on single-motor cars though since the draw from one motor doesn't usually exceed the power available from an L2 charger, thus people see different results in seemingly similar circumstances.

 

[SammichLover]

Wait, where are you saying the power for heating comes from then?

"....the car will sometimes use the wall source to use the motor to circulate heat into the battery..."

How is this not entirely clear?

That you were unable to "decode" this however helps explain a lot about your posts, and overall level of ignorance and things like.....

The thought that the car only ever takes power from the wall and not the battery when plugged in is yet another myth, actually.

Pump the brakes on that straw man erection, please.

 

[TEG]

The usual EV conspiracy theories:

#1: It pollutes more than a gas car because all your electricity comes from burning coal...
#2: The battery will only last 5 years then you have to junk the car.
#3: The battery will catch fire by itself.
#4: It can't be any fun because it doesn't make engine noises.

 

[john5520]

Myth: It's maintenance free!

Yeah, some people treat their ICE vehicles this way too. They sometimes tolerate it for a very long time, just like Teslas! Until they don't.

Myth: You save so much money compared to a new gas car!

If you compare to a new gas car of the same price out the door, sure. That's dishonest since EVs just cost more right now. Most local Model 3 buyers are coming from more mainstream stuff like Hondas and Fords that are definitely cheaper. Especially if you need the Long Range models, there isn't much money to be "saved" (if any).

I can't speak for other EVs, but a comparable ICE to the LR AWD (even with FSD) in terms of performance and tech features is about the same price or higher and generally need premium fuel. Now add the higher maintenance cost to the equation, and the Tesla will very likely be cheaper and more reliable in the long run and have a better warranty. Now, what's funny is, if you add the 2k boost option which brings the performance down to sub 4 seconds (~3.7-3.9) and <12 sec quarter (~11.8 sec), you'll have to start searching for an ICE close to 80k or more to compare. Sure, you might get nicer interiors and more luxury features, but I could give 2 craps about that.

I mean... they're as for "rich people" as is any other car you'd get at the same price. People stretch their finances to buy a Tesla sometimes, but that doesn't mean it's an affordable car. As an EV it is indeed more expensive than other cars by default.

Like I stated above, when you consider the performance / tech and long term fuel / maintenance cost savings, it's a bargain.

 

[JayNJ]

Damm, no one posted my fav one to hear..."Those things catch fire all the time, its a deathtrap"

Followed by the battery constantly needs replacing an its 10k for one.

Yeah definitely not only 10k for a new battery. But thankfully you won't have to replace it for quite a while out of warranty.

 

[JayNJ]

Following up your continued cliche delusion about comparable vehicles with another Not-A-Myth! Woot, you’re on a roll!

If the vehicle is plugged into a charger the car will sometimes use the wall source to use the motor to circulate heat into the battery, but it never comes out of the battery. This battery conditioning is done in part because charging works better and is safer for the battery at something closer to around 80F-90F (keeping in mind that charge running into the battery also heats it, too).

The battery charge level does drop parked in the cold if not plugged in but that is because of lower temp -> lower chemical reaction rate.

The car will keep the battery above dangerously low conditions. So it will definitely use battery, but not to preheat like when plugged in, just to prevent damage.

 

[SammichLover]

The car will keep the battery above dangerously low conditions. So it will definitely use battery, but not to preheat like when plugged in, just to prevent damage.

The Model 3 doesn't heat the battery itself, although you can have it work on the cabin which is a different thing. Heating the battery with the battery's power would be counterproductive to any 'protection' of the battery from cold. It'll use the battery to protect from heat and there is always the ongoing vampire drain, though.

Heat degrades just being there, the problem with cold is more-so to do with charge-discharge. It greatly increases internal resistance, so you can think of trying to charge a very cold battery as forcing it, too hard. This is the reason the BMS so sharply reduces regen, which is really a form of battery charging, when your pack is colder.

P.S. Note that IIRC the center screen now shows the BMS limiting on regen for hot extreme closer to the top of battery fill. Tesla sculpted the curve a bit more, they must have been seeing the heat generated from regen charging being a bit too much further down the charge level.

 

[Yev000]

My favorite myth: FSD will be available by the end of "this" year.

Not sure thats a "myth" per say - "a widely held but false belief or idea." Not sure how many people actually belive Elon when he talks about FSD.

 

[hcdavis3]

Just take the red pill. Easy.

 

[birdsquared]

Well, looks like Tesla itself has decided to end the myth that the dual motors will drive on a single motor when needed - the updated text on their website just talks about 'redundancy':
Tesla All-Wheel Drive has two independent motors for improved redundancy, each with only one moving part for minimal maintenance and maximum durability. Unlike traditional all-wheel drive systems, they digitally control torque to the front and rear wheels for far better handling and traction control.

 

[SammichLover]

Well, looks like Tesla itself has decided to end the myth that the dual motors will drive on a single motor when needed - the updated text on their website just talks about 'redundancy':
Tesla All-Wheel Drive has two independent motors for improved redundancy, each with only one moving part for minimal maintenance and maximum durability. Unlike traditional all-wheel drive systems, they digitally control torque to the front and rear wheels for far better handling and traction control.

It isn’t truly a myth. It is something that doesn’t happen that often, but it does happen that the vehicle will proceed with one failed DU for certain kinds of failures.

It just really isn’t much of a selling point in the actual, and lots of ways for a single DU failure to require a flatbed anyway.

 

[birdsquared]

It isn’t truly a myth. It is something that doesn’t happen that often, but it does happen that the vehicle will proceed with one failed DU for certain kinds of failures.

It just really isn’t much of a selling point in the actual, and lots of ways for a single DU failure to require a flatbed anyway.

It was a specific feature touted by Tesla, and it was a selling point to me in deciding to
choose the AWD version (a minor one, but still). And it appears it was a myth, given that there were very few circumstances in which the vehicle would continue to drive with only one motor.

 

[SammichLover]

(a minor one, but still)

That is befitting of a minor benefit. Although it does ride the edge of inconsequential benefit.

 

[wtwieder]

It is a myth that you need a long extension cord when driving any electric car.

 

[zhu-]

I had someone tell me they would consider it if Tesla had a backup spare battery built into the car. I said, if you knew you had a spare battery, you'd just assume your car had the full range the entire time so what's the point? You could mentally limit off 10% of your range and pretend that's the "spare battery". He said "nah it's different."

 

[gavine]

I had a neighbor say "how do you sleep at night knowing you have lithium-ion batteries in your garage that could catch fire". My reply was, "You have a cell phone on your nightstand and/or in your pocket, right?"