Battery degradation warranty question.

[AidanR]

My lifetime average over 25000 miles is just on 350w/mile. I did a cold weather run from Aberdeen to Preston the other day and with a bit of careful driving and battery preconditioning before leaving home I managed to get to Tebay (circa 250 miles). I don’t like doing this in winter but both Abington and Gretna were full. As a rule of thumb I use 250 to 300 miles range in summer and 200 to 250 in winter and this still seems to hold good for me. Your 550 w/mile seems very high to me. Even with heater and lights on and 70mph on motorways I am generally under 450. It’s a 100kw pack.

I think you are right!…. So I drove really gently today and got the figure down to below 399wh/mi!… even though the total range wasn’t really my issue here, I think I need to adapt my driving style!!! I hadn’t realised how much difference it would make!!! Thanks again, you’ve saved me a fortune in charging for this next year! I’ve never even seen the wh/mi start with a 3, let alone a 2!!!

 

[Jason71]

Resolved- so after all the help on here, and also tesla rang me back with some helpful info…. The 68.7kw I’m seeing in the display as ‘since last charge’ doesn’t include any auxiliary services like heating, the figure is purely for driving- so the ‘missing 30kw or thereabouts is winter auxiliary things like heating, which makes perfect sense…..

Unless the X is very different to the 3/Y then the "since last charge" DOES include things like heating and lights but it only includes those things if they were used WHILE DRIVING. Those are the things that make the wh/m so much higher
What it does not include is any static usage such as:
Sentry mode
phantom Drain
preheating
or any other energy used while sitting in the car in "Park".

 

[yessuz]

I think you are right!…. So I drove really gently today and got the figure down to below 399wh/mi!… even though the total range wasn’t really my issue here, I think I need to adapt my driving style!!! I hadn’t realised how much difference it would make!!! Thanks again, you’ve saved me a fortune in charging for this next year! I’ve never even seen the wh/mi start with a 3, let alone a 2!!!

I have quite long commutes every week, 160 miles each way.
I always use AP and set speed to 72 mph - in this case half of the time I am in the outside lane anyway and I have reasonable wh/mite numbers.

speed, temps and conditions are main factors. short trips tend to consume more, cold battery as well...

my model 3 has heat pump so that is no biggie. but for example same road trip when it is dry vs rain causes 10% points higher battery usage for the same trip (I arrive with 40% vs 30% remaining)

 

[Jason71]

I think you are right!…. So I drove really gently today and got the figure down to below 399wh/mi!… even though the total range wasn’t really my issue here, I think I need to adapt my driving style!!! I hadn’t realised how much difference it would make!!! Thanks again, you’ve saved me a fortune in charging for this next year! I’ve never even seen the wh/mi start with a 3, let alone a 2!!!

Its not just your driving style its your heating style. As I mentioned before if you are commuting alone try turning the heated seat up and the heater fan speed to low. This limits the output of the heater. X is a big beast and the car is trying to heat a large volume of air most of which is unoccupied. In cold weather this can make a significant difference.
I have done this while commuting in winter in an M3 and I did not find any loss of comfort but a noticible improvement in efficiency.

 

[WannabeOwner]

or something like Tessie that I use. Even if you just do the free trial, it will give you your battery health. Granted I'm not sure what info they use to calculate it mind

As another option I similarly recommend TeslaFI.COM

I don't know about Tessie, but TeslaFi benefits from having historical data. It will only record from when you start using it, and its battery degradationgraph will give you the range you achieved at various points in the car's (well the "recorded data's") history. You can fiddle with the filters, but the one I use is to only include 100% (or maybe 99%) charges - so it bases the graph on occasions when the car was fully charged (which would also cause the cells to be rebalanced and [apparently!] that then improves the range estimating).

But, either way, TeslaFi does give you a comparison with the fleet, as @scottf200 illustrated, so that could be useful even in a trial version. Worth doing a 100% charge during the trial to be able to single out / filter that specific figure on the degradation graph.

I charged to 100%, then drove to 0% or 0 miles a without charging (made sure I was round home/near a charger near the 0% part for obvious reasons lol)…… I then took the dashboards display of ‘kw used since last charge’

Helpful advice has been posted here (and looks like you have it sorted). Bjorn Nayland has some useful YouTubes on how he has calculated range (when testing a brand new make / model etc.). Still need an equivalent figure for "when new", but something representative should be available online somewhere

get 122 miles from 100% to 0% charge, I used to get 220 ish. I use about 510wh/mi on Ave

Your 550 w/mile seems very high to me

I agree, I think 510wh/mile looks like a big number to me too. Important to make sure that cabin and battery heating are not getting wrapped up in that figure - e.g. by fully precondition the car [from Grid] before setting off for a (consumption test) long trip. The heater etc. consumption should then be reasonably well averaged out for the trip (the longer the trip). I don't think you need to drive to 0%, just as low as you can reasonably get in a single-leg.

Winter will make a big difference. less so on long journeys but still a big difference. you are likely to see a winter range drop of 20+%.

My winter experience is not that severe. If I pre-condition the car, and don't stop (i.e. which would let the battery cool down, and use energy to heat it back up again) I reckon that winter (around 5C) uses 10% more than Summer. Certainly if the temperature is "Artic" it will be a lot worse, but most of my winter driving is 5C-ish and if it is -10C the AA and RAC will be saying "Don't go anywhere" so I hide behind that if someone thinks they need me to visit them!

A Model-X of "some vintage" probably has a "Range Mode". Turning that on will be somewhat more frugal (on journeys where range is key) at the expense of some cabin heating.

 

[Sean.]

I’ve done some basic Calcs and think my battery is around the 70% degradation mark, it’s a 2019 model X and it’s done around 50k miles.

My 100D Model X is older with more miles than yours (5 years old with 80,084 miles). The Tessie app reports a 6.4% degradation. So 91 kWh useable capacity.

What does yours report?

 

[Jason71]

My winter experience is not that severe. If I pre-condition the car, and don't stop (i.e. which would let the battery cool down, and use energy to heat it back up again) I reckon that winter (around 5C) uses 10% more than Summer. Certainly if the temperature is "Artic" it will be a lot worse, but most of my winter driving is 5C-ish and if it is -10C the AA and RAC will be saying "Don't go anywhere" so I hide behind that if someone thinks they need me to visit them!

Maybe so but you are quoting the best case scenario for winter. No extreme temps, single journey after a good preheat.
I am talking about my average range over the course of the seasons and including plenty of short journeys. and I don't think overall 20% is far off
Unless I need the range I only preheat minimally (5-10 minutes) to warm the cabin.
No point giving it 20 minutes+ to warm the battery. If plugged in its a waste of money since I would be using day rate electrons while parked to to save on night rate electrons while driving. If not plugged in then also no point, zero sum game.

 

[DrJFoster]

My results using the link on Georges post. It's a different model but shows how its calculated, your results will of course be different.

 

[WannabeOwner]

I am talking about my average range over the course of the seasons

Two scenarios then ..

I take the view that for short journeys I'm not going to run out of fuel, and therefore consumption doesn't matter i.e. it is what it is. However, it is relevant to the cost of running the car (and an ICE would also have poor consumption; I don't know if the two are comparable in that regard, but both are "suboptimal"!), and it would also be relevant to someone who didn't have home charging and would have to travel to get a charge - that activity is going to happen more often in Winter than Summer.

So for me the only "Extra consumption" figure that matters is for a long journey, which is either out-of-range or range-challenged, and for me 10% is a reasonable figure; from where I start 5C is a likely average temperature for a winter journey. I certainly agree that my overall winter consumption "cost" is likely to be 20% more; on my short journeys I'm never organised enough to turn climate on before I leave (Grid might be, say, 10% more efficient than via-Battery, but overall the car still needs warming up, and as you say Day Electricity more expensive than Night). But for a long / range-challenged journey I aim to always pre-condition.

 

[AidanR]

I don't know about Tessie, but TeslaFi benefits from having historical data. It will only record from when you start using it, and its battery degradationgraph will give you the range you achieved at various points in the car's (well the "recorded data's") history. You can fiddle with the filters, but the one I use is to only include 100% (or maybe 99%) charges - so it bases the graph on occasions when the car was fully charged (which would also cause the cells to be rebalanced and [apparently!] that then improves the range estimating).

But, either way, TeslaFi does give you a comparison with the fleet, as @scottf200 illustrated, so that could be useful even in a trial version. Worth doing a 100% charge during the trial to be able to single out / filter that specific figure on the degradation graph.



Helpful advice has been posted here (and looks like you have it sorted). Bjorn Nayland has some useful YouTubes on how he has calculated range (when testing a brand new make / model etc.). Still need an equivalent figure for "when new", but something representative should be available online somewhere





I agree, I think 510wh/mile looks like a big number to me too. Important to make sure that cabin and battery heating are not getting wrapped up in that figure - e.g. by fully precondition the car [from Grid] before setting off for a (consumption test) long trip. The heater etc. consumption should then be reasonably well averaged out for the trip (the longer the trip). I don't think you need to drive to 0%, just as low as you can reasonably get in a single-leg.



My winter experience is not that severe. If I pre-condition the car, and don't stop (i.e. which would let the battery cool down, and use energy to heat it back up again) I reckon that winter (around 5C) uses 10% more than Summer. Certainly if the temperature is "Artic" it will be a lot worse, but most of my winter driving is 5C-ish and if it is -10C the AA and RAC will be saying "Don't go anywhere" so I hide behind that if someone thinks they need me to visit them!

A Model-X of "some vintage" probably has a "Range Mode". Turning that on will be somewhat more frugal (on journeys where range is key) at the expense of some cabin heating.

Thanks, that’s a good idea to pre-condition from grid- I don’t do that, but it makes a lot of sense as the first mile in the morning usually has 1000+ wh/mi, so some sort of heating is going on…

Regarding the heat pump, I’m not sure, I get the amber symbol in the app when the battery is warming up when I select a supercharger to nav to.

I do have that range mode, I thought all cars have that, but if not, mine definitely has it so I’ll try it.

Gonna try an app to log just for finding out, and it’s interesting that wh/mi figure might include heating when driving, I’ll try that too, but I must admit that yesterday with the heat off I didn’t notice and drop in cabin comfort.

Thanks again for all the comments

 

[AidanR]

The short journeys thing might be my issue too…. My 100 mile commute involves stopping at up to 10 places, so it’s a lot of stop start, plus every time I walk past the car it unlocks with the key in my pocket, so not sure how much this constant’waking’ of the car affects the figures?

 

[WannabeOwner]

do have that range mode, I thought all cars have that

Only S and X I think (maybe Performance 3/Y also have it?

Gonna try an app to log just for finding out

if you are going to try TeslaFi then if you register with a referral code the trial is increased from 2 weeks to a month. If you don't have a better offer you can use my forum handle.

My 100 mile commute involves stopping at up to 10 places

The "travelling salesman" is worst case for winter range. Warm the car nicely before you set off, and then ever stop for a hour or so cold-soaks the cabin and battery, and then needs loads of energy to warm them up each time you set off.

Even plugging into a 13AMP socket lying around the carpark! would help (e.g. if you are tight for range that day)

 

[Jason71]

The short journeys thing might be my issue too…. My 100 mile commute involves stopping at up to 10 places, so it’s a lot of stop start, plus every time I walk past the car it unlocks with the key in my pocket, so not sure how much this constant’waking’ of the car affects the figures?

if you leave sentry mode on then the car will be awake ALL the time and if the same as a 3/Y will be using 200-300wh per hour while parked. put that in perspective that is 5-7.5% of your battery if you left it for 24 hours or 0.2-0.3% per hour which is definitely not nothing.
however
if you have sentry turned off then after 15-20 minutes parked the car will go to sleep and use next to nothing. but for 15-20 minutes after every stop you are using the equivalent of 200-300wh/hour.
and of course when stopped the car and battery cool down and have to be warmed up again. in winter this will likely dwarf the being awake impact

I would say this is more "delivery driver" than "traveling salesman" but either way very bad for efficiency

 

[Sean.]

Speaking of delivery drivers. I wonder how Amazon and Rivian are going on their testing?

 

[AidanR]

Just an update on this range issue- my front brake pads needed changing last month, I decided to do them myself, but noticed one side the pads had rusted stuck when I was changing them, I cleaned the calliper and fitted the new pads- instantly a 20%+ increase in range compared to before the pad swap, I’ve probably done 1500 miles since the pad swap, the 20%+ range increase appears to be consistent…. So I’m now thinking the brakes had been binding for quite some time and as I was effectively driving around with the brakes on all the time, it’s likely that caused my range issues to be even more noticeable in those winter months above!!… summer time wh/mi have gone from about 460wh/mi to 350wh/mi now! This also makes sense with one of the comments above about my winter 550wh/mi being really high compared to their identical model.

In summary, I hope this helps someone else In The future that’s puzzled by sudden range issues to maybe check their brakes aren’t binding too!!

 

[Adopado]

Just an update on this range issue- my front brake pads needed changing last month, I decided to do them myself, but noticed one side the pads had rusted stuck when I was changing them, I cleaned the calliper and fitted the new pads- instantly a 20%+ increase in range compared to before the pad swap, I’ve probably done 1500 miles since the pad swap, the 20%+ range increase appears to be consistent…. So I’m now thinking the brakes had been binding for quite some time and as I was effectively driving around with the brakes on all the time, it’s likely that caused my range issues to be even more noticeable in those winter months above!!… summer time wh/mi have gone from about 460wh/mi to 350wh/mi now! This also makes sense with one of the comments above about my winter 550wh/mi being really high compared to their identical model.

In summary, I hope this helps someone else In The future that’s puzzled by sudden range issues to maybe check their brakes aren’t binding too!!

Good points. This is why Tesla recommends brake service.

 

[Jason71]

Just an update on this range issue- my front brake pads needed changing last month, I decided to do them myself, but noticed one side the pads had rusted stuck when I was changing them, I cleaned the calliper and fitted the new pads- instantly a 20%+ increase in range compared to before the pad swap, I’ve probably done 1500 miles since the pad swap, the 20%+ range increase appears to be consistent…. So I’m now thinking the brakes had been binding for quite some time and as I was effectively driving around with the brakes on all the time, it’s likely that caused my range issues to be even more noticeable in those winter months above!!… summer time wh/mi have gone from about 460wh/mi to 350wh/mi now! This also makes sense with one of the comments above about my winter 550wh/mi being really high compared to their identical model.

In summary, I hope this helps someone else In The future that’s puzzled by sudden range issues to maybe check their brakes aren’t binding too!!

Easy way to check. Check the disk temp at the end of a drive. A laser thermometer is good for this. I don't recommend touching the disk. I did this once to check for binding. It did not end well

 

[MrBadger]

Easy way to check. Check the disk temp at the end of a drive. A laser thermometer is good for this. I don't recommend touching the disk. I did this once to check for binding. It did not end well

You normally get a raised wheel rim temperature if a brake has been binding for any length of time. You can feel it best at the centre of the wheel and should be safe to briefly touch by hand. I normally use back of hand as it normally a bit more tolerant to excess heat.

 

[Jason71]

You normally get a raised wheel rim temperature if a brake has been binding for any length of time. You can feel it best at the centre of the wheel and should be safe to briefly touch by hand. I normally use back of hand as it normally a bit more tolerant to excess heat.

Agreed but If one is binding it will be much hotter than the others so it's the relative temperature to check. And i got a nasty burn trying to check that on a model 3