Available kWh in Standard and Range Mode for Model S?

[stopcrazypp]

Well, Tesla's going to need to find a way to make that discussion possible because people are going to want to know and they'll feel very uncomfortable and untrusting with vague answers.

Then that sounds like the educational material Tesla needs to put together. I'm not trying to be a hardass here, people are going to want to know. George B even talks about how the stores are about educating people on EVs. This seems like a good fit of purpose.

The problem is most people don't give a sh*t about these specifics (you can tell by how much the general public knows about ICE cars). Some people are enthusiastic (like us), most people don't care. You can see the battery bricking issue for a fine example (Tesla laid out a very clear description of the discharge timing in the manual that was largely ignored).

This is just quibbling semantics. It all boils down to "I do X and the battery gets worse by Y". Very few people, including fairly technical people like me, are going to care about the technical classifications of why Y gets worse. You might argue they should care, but that's fighting human nature and that battle is lost before it's started.

It's not just "semantics". "Damage" is orders of magnitude worse than "wear" and is usually used to describe issues that lead to the need for immediate total replacement or repair of a part, which is why it's not used except in very specific situations. For example, there are certain roads that put extra wear on tires, but you would not call it "damage". However, if a nail punctured your tire, it would be called "damage".

In the same vein, charging in Range mode (and storing it for long periods of time, like the worse case I point out) would not lead to your battery needing immediate replacement or repair. The battery will just wear faster than normal. As in your 1 year old battery looking as if it's a 3 year old battery. However, if you fully discharged it and left it there so that it is under-voltage (this is real damage), your battery would need replacement or repair.

 

[ckessel]

It's not just "semantics". "Damage" is orders of magnitude worse than "wear" and is usually used to describe issues that lead to the need for immediate total replacement or repair of a part...

Smoking damages my lungs.
Lack of oxygen damages the brain.
Pollution damages fish runs.
Bruising damages the apple I'm going to eat for lunch.

I do understand what you're saying, but it's common for "damage" to mean "diminished capacity" or "excessive wear". In Oregon, there have been numerous articles over the years about how studded tires "damage" the roads though it's basically excessive wear.

 

[smoothoperator]

Tesla Roadster Battery Care

 

[brianman]

Yah, that's the post to which I was referring.

 

[gg_got_a_tesla]

Tesla Roadster Battery Care

Dan Myggen appears to have moved on recently to a role as a Training Developer at Tesla; given the quality of that response regarding the Roadster battery, that augurs well for Model S owners.

 

[kevincwelch]

I'm with ckessel on this one.

The Model S is not the Roadster, so while it is nice to project the outcome of the Roadster on the Model S, it isn't going to be accurate. I think the reason why this battery issue is such a polarizing issue is purely because Tesla hasn't been very forthcoming about it the whole issue other than to sheepishly admit that the Model S hasn't been around long enough to test the battery.

To put this issue at rest, Tesla needs to do the following:

1. Give us the warranty in plain writing.
2. Specify what constitutes normal use.

 

[Doug_G]

Dan Myggen appears to have moved on recently to a role as a Training Developer at Tesla; given the quality of that response regarding the Roadster battery, that augurs well for Model S owners.

Dan is now in charge of training the guys who will deliver your Model S's.

 

[Doug_G]

If 53 of 56 kWh is available in the Roadster, that would mean about 95% of the battery would be available in Range mode.

Funnily enough when I've got a full Range mode charge, my log parser also shows SOC at 95%.

 

[EarlyAdopter]

FWIW, running an ICE car down to near empty before every fill can over time cause problems, too.

The reasons are varied - impurities floating to the top, sediment settled at the bottom, more air volume for water vapor to condense - but the impact to the fuel system and engine is said to reduce fuel efficiency over time, thus range.

As a precaution I try to refill my car when it hits a 1/4 tank, so my range is cut by 20-25%, too. Seems reasonable to me to do the same with an EV.

 

[smoothoperator]

FWIW, running an ICE car down to near empty before every fill can over time cause problems, too.

The reasons are varied - impurities floating to the top, sediment settled at the bottom, more air volume for water vapor to condense - but the impact to the fuel system and engine is said to reduce fuel efficiency over time, thus range.

As a precaution I try to refill my car when it hits a 1/4 tank, so my range is cut by 20-25%, too. Seems reasonable to me to do the same with an EV.

If you ran a Tesla Roadster (cannot comment on the Model S since no data is available but I would assume it would be similar) to this point (before every fill i.e. charge), irreversible battery damage would occur. In an ICE motor you would likely only have to change the fuel filter.

 

[stopcrazypp]

Smoking damages my lungs.
Lack of oxygen damages the brain.
Pollution damages fish runs.
Bruising damages the apple I'm going to eat for lunch.

I do understand what you're saying, but it's common for "damage" to mean "diminished capacity" or "excessive wear". In Oregon, there have been numerous articles over the years about how studded tires "damage" the roads though it's basically excessive wear.

All of the examples you give have extremely bad connotations and have immediate results you can see when you examine the "damaged" subject.
Lung damage from smoking can be immediately seen from the damaged cells in your lungs.
Brain damage from lack of oxygen can be immediately seen from dead brain cells.
Pollution damage on fish runs can be immediately seen from order of magnitudes more dead fish (not natural deaths).
Bruising damage on your apple can immediately be seen from the brown marks.

This is not the same as what you call "damage" when charging in Range mode. The only sign is the battery looks older if you do it regularly (there will be no measurable immediate results). There's no evidence of "damage" at all. The battery is still operating in its normal window of operation (0-100% SOC). While in a over-charge or over-discharge situation, you will see immediate "damage" (swelling or venting of cells, immediate lost of a couple percent of SOC and continued accelerated loss afterwards even in normal charging conditions, higher impedance and thermal instability).

The closest point you have is the example of excessive wear of studded tires, although from what I can tell, the wear from studded tires can be an order of magnitude worse (requiring in the worse case, annual or biannual repaving vs. the 14 and 25 year life span of Oregon asphalt and PCC roads) and they use "damage" to describe it clearly because it sounds (and implies) much worse than just "excessive wear". Plus studded tires can actually chip at the pavement (not just rub against it).
http://preservingoregonsroads.org/wp-content/uploads/2012/03/UseEffects.pdf

 

[ckessel]

All of the examples you give have extremely bad connotations and have immediate results you can see when you examine the "damaged" subject.

Fine, if you feel you have to "win", then I concede.

 

[W8MM]

Fine, if you feel you have to "win", then I concede.

Why can't we just admit that EV battery packs are wear parts, just like clutches and brake rotors, pads, and shoes, and tires?

They wear out. Are brake rotors "defective" when they reach end of life?? Or, are they just worn out because of usage patterns?

I, too, think that characterizing consumption goods as infinite-life investments is the wrong way to think about them. Your choice of debate terms reveals an insight into your thinking over which nobody is trying to "win", maybe just enlighten.

 

[ckessel]

Why can't we just admit that EV battery packs are wear parts, just like clutches and brake rotors, pads, and shoes, and tires?

Yep, I'm fine with that. I even said I understood the point and my only point was that a common meaning of "damage" is fairly analogous with degradation.

FWIW, Websters: damage[verb] - to reduce the soundness, effectiveness, or perfection of.

Does range charging reduce the soundness, effectiveness, or perfection of the battery?

 

[ddruz]

So one potential answer to my question is that Standard mode allows 80% of the battery capacity to be used. Somewhere else on internet.com or this forum, I've seen the figure 3.5 miles per kWh thrown out for the average Model S efficiency. Using these figures, usable range is:

40 kWh pack
32 kWh usable
112 miles of range

60 kWh pack
48 kWh usable
168 miles of range

85 kWh pack
68 kWh usable
238 miles of range

Again, these are just estimates based on assumptions of 80% charge available in Standard mode and an average efficiency of 3.5 miles per kWh.

Remember, we do not know yet whether the 60 or 40 kwh cars weigh significantly less than the 85 kwh car on which we have data. If they do, the miles/kwh will be proportionately higher for the smaller battery pack cars. For example, my Leaf which weighs about 3350 lbs easily gets 4.4 miles/kwh and can get over 5.0 miles/kwh if I drive conservatively.

 

[EarlyAdopter]

If you ran a Tesla Roadster (cannot comment on the Model S since no data is available but I would assume it would be similar) to this point (before every fill i.e. charge), irreversible battery damage would occur. In an ICE motor you would likely only have to change the fuel filter.

Not according to the folks at Edmunds:

The lower your car's gas level sinks, the more the dirt gets stirred up from the bottom of the tank. Drive on a near-empty tank and you risk this dirt getting into your car's fuel line and even into the engine. There's a good chance your car's fuel filter won't be able to catch all of it, especially if you drive with a barely filled gas tank on a regular basis.

"You're going to pull the heaviest sediment into the fuel line," says Karl Brauer, editor-in-chief at Edmunds.com. "If it gets all the way to the engine, it could scar or damage internal parts of the engine."​

From: Bad driving habits can wreck your wallet

 

[Lloyd]

Not according to the folks at Edmunds:

The lower your car's gas level sinks, the more the dirt gets stirred up from the bottom of the tank. Drive on a near-empty tank and you risk this dirt getting into your car's fuel line and even into the engine. There's a good chance your car's fuel filter won't be able to catch all of it, especially if you drive with a barely filled gas tank on a regular basis.

"You're going to pull the heaviest sediment into the fuel line," says Karl Brauer, editor-in-chief at Edmunds.com. "If it gets all the way to the engine, it could scar or damage internal parts of the engine."​

From: Bad driving habits can wreck your wallet

Also the newer "in the tank" pumps depend on fuel for cooling. Pumps that are run near empty have been purported to have a shorter life span. Replacements are also more expensive. Chevy now requires replacement of the tank as well as the pump. $500+ and several hours of labor.

 

[smoothoperator]

Not according to the folks at Edmunds:

The lower your car's gas level sinks, the more the dirt gets stirred up from the bottom of the tank. Drive on a near-empty tank and you risk this dirt getting into your car's fuel line and even into the engine. There's a good chance your car's fuel filter won't be able to catch all of it, especially if you drive with a barely filled gas tank on a regular basis.

"You're going to pull the heaviest sediment into the fuel line," says Karl Brauer, editor-in-chief at Edmunds.com. "If it gets all the way to the engine, it could scar or damage internal parts of the engine."​

From: Bad driving habits can wreck your wallet

How does sediment get past a filter? you may see a restriction or perhaps if someone pokes some holes in the filter? If the sediment is small enough the secondary fuel filter will catch it, no? Using your scenario lets say that this is true....Do you believe that running on low fuel consistently will cause as much damage to an ICE motor as it would (running a low SOC cosistently) with an EV? I have never seen a warranty document from a major auto manufacturer that states that if you run your vehicle on a very small amount of fuel consistently your warranty is voided (or if you run out of gas consistently). I have seen a document from Tesla stating that if you do not plug your vehicle in your warranty is voided and that you may cause irrepairable unwarranted damage to your battery. Please advise

 

[jerry33]

1. In modern cars the fuel is pumped from the bottom of the tank. There is really no place for any dirt to settle--except in the fuel filter.
2. The fuel pumps in modern cars don't just keep running when the tank is empty and burn out (some early ones did, but that was years ago).

This is another topic, like tires, upon which there is a lot of garbage floating around. What was true in 1930 era cars isn't generally true today.

 

[Vger]

Having owned a Roadster for two years, I can say this: Tesla designed Range and Standard mode to avoid the most wearing/damaging (pick one!) thing to an Li-Ion battery-- sitting for a LONG period of time either chock full or very empty-- especially when hot. A Tesla battery, ANY Tesla battery, even the 40 kWh Model S battery, is FAR larger than needed for the vast majority of routine driving by most people. So one only really needs to use Range Mode for relatively infrequent road trips, and when one does, one begins discharging or re-charging the battery very quickly after achieving a full charge or reaching a low charge. So in this scenario the "wear/damage" is minimized because it is the TIME spent at these levels that has the effect. I have done 1,000's of miles of road trips in our Roadster, using dozen of range mode cycles over two years, and total wear on the battery (from ALL activities, including shelf life) is barely detectable-- maybe 1-2% of capacity.

So by encouraging people to use Standard Mode for the VAST majority of routine driving, battery life is maximized while putting only the tiniest burden on the user to pay attention to the need at hand. If people were allowed/encouraged to use the full capacity of the battery routinely, by charging to the gills every night, they would be letting the car sit there for a cumulative thousands of hours cooking its chemistry for no good reason at all!

First time Model S buyers, be very grateful to the the brave pioneers before you who have accumulated over 25 MILLION miles of experience, with an astonishingly few problems! And also be grateful that your battery is not sized to be used to the max constantly, like all of the current competition!