Still not sure about battery display!

[bohenriksson]

Sorry since there’s a million posts on this (and I’ve spent hours reading them..)
But I’m still not sure what the consensus on the battery /range display is:

My 6 months 3 w about 10 000 miles now showing an extrapolated range of around 295 miles. Regularly charge to % 80 with occasional 90 and one or two 100.
The advice on this board is to switch to showing battery percentage.
So the question is, percentage of WHAT?
The original kWh rating or the current (slightly degraded) actual capacity?

Lifetime average efficiency is 254 Wh/mile. Since this was during the cold season with lots of heating I expect this to get better.

And no, not worried about it just curious.

Thanks!

 

[jdw]

On the display preference tab, you can choose to display Energy or Miles. Energy is percentage charge, miles is rated miles.

 

[animorph]

No percent in Canada?

I assume 100% would mean the battery is at maximum charged voltage. That voltage does not change with battery degradation. So that 100% would represent fewer kWh's of energy as the battery degraded. One reason I do not use the battery percent display. I haven't heard of lots of people complaining their car only charges to 94% now due to battery degradation (though sometimes a problem will cause that to happen).

 

[kr200]

On the display preference tab, you can choose to display Energy or Miles. Energy is percentage charge, miles is rated miles.

I've been using miles/kilometers since 2013 on my MS. It's a fixed miles/charge. In other words in EPA standard conditions it will go the indicated miles. Half the full mileage indication is 50% charge. It tells me how far I can go running the battery to 0% charge under EPA conditions which are approximately 70F, flat road, and constant speed of about 65mph. If I slow to 60 I'll go further. If I speed up to 70 I won't go as far. If I accelerate/brake frequently I'll get less than indicated. If it's cold I'll get less. If I use heat or AC I'll get less. If there is a headwind, wet, snow, tire pressure, tire type, etc., I'll get less. Switching to % just involves an extra calculation and gives NO ADVANTAGE. Mileage also gives an indication of battery degradation, which % does not. In other words a given charge % will give a reduced indicated mileage as the battery degrades with age and mileage.
You might have to charge to full a few times a year to re-balance the cells and get a proper calibration of the battery capacity. It's also possible Tesla updates might change the calibration.
I'll stick to the distance indication!

 

[bohenriksson]

Thanks kr200! That’s been my understanding too (although others seem to think differently), that remaining range shown is just number kWh (day 75 fully charged) divided by a constant (read somewhere it’s 250 wH/mile for the 3, which is about what I’m getting), in this case giving 300 miles.
My fully charged range dropped quite a bit with one of the recent updates (from say 302 to 295) and maybe it’ll come up with a new software? I’ve got some long trips coming where I’ll charge to full, we’ll see if that changed anything. Either way, the 3 is a great car and a joy to drive!

 

[jelloslug]

Thanks kr200! That’s been my understanding too (although others seem to think differently), that remaining range shown is just number kWh (day 75 fully charged) divided by a constant (read somewhere it’s 250 wH/mile for the 3, which is about what I’m getting), in this case giving 300 miles.
My fully charged range dropped quite a bit with one of the recent updates (from say 302 to 295) and maybe it’ll come up with a new software? I’ve got some long trips coming where I’ll charge to full, we’ll see if that changed anything. Either way, the 3 is a great car and a joy to drive!

It's not that simple (and it never has been). There are other variables that play into the calculation (even though many people here are adamant that there are not). It's easy to observe this by taking a nice long road trip, bringing your average usage down a bit, and watch your indicated range go up. Regardless of that, I have found that the percentage of charge remaining is much more useful since it's an actual indication of what is available. When you have an indicated range of say, 200 miles, it's quite easy to get 250 miles or 150 miles. If it's 72% charge remaining, it's 72% no matter how you drive.

 

[jdw]

It's not that simple (and it never has been).

The biggest variable is how much capacity your car (BMS) thinks your battery has - that number, divided by your cars Wh constant equals your rated range in km or miles. All drives are not the same - a number of 2 mile drives, especially in cold weather, will not use the same energy as a single drive covering the same distance,

So if the battery is cold, or if you only charge to 70 or 80% daily, or if you let the car sit at a lower state of charge, especially with no charging, for long periods of time, your BMS will gradually become inaccurate and the battery capacity your car thinks you have will drift lower and your displayed rated range will drop, usually causing worried posts here.

None of the range or capacity displays are 100% accurate, although the projected range in the energy graph will be the closest as it captures current driving and battery conditions and is not dependent solely on a static number calculation.

As "rated miles" is so variable and irrelevant, I switched to percentage display years ago. With a 100kWh battery and 550 km range, if I need to estimate range quickly, I multiply percent remaining by 5 and that gives me a good estimate with a 10% safety buffer. If your range is 300 miles, then 60% battery = about 180 mile rated range. Using percentage is pretty much like usiing the gas gauge in an ICE vehicle.

Everyones preferences will vary.

 

[jjrandorin]

Sorry since there’s a million posts on this (and I’ve spent hours reading them..)
But I’m still not sure what the consensus on the battery /range display is:

My 6 months 3 w about 10 000 miles now showing an extrapolated range of around 295 miles. Regularly charge to % 80 with occasional 90 and one or two 100.
The advice on this board is to switch to showing battery percentage.
So the question is, percentage of WHAT?
The original kWh rating or the current (slightly degraded) actual capacity?

Lifetime average efficiency is 254 Wh/mile. Since this was during the cold season with lots of heating I expect this to get better.

And no, not worried about it just curious.

Thanks!

Why not try NOT "regularly charging to 80%", and just set it to 90% and leave it plugged in (especially now that we are sheltering in place). It may take a couple weeks of "leaving it at 90% and just plugging it in", but I would bet your "range comes Back" if you do that.

TMC has convinced everyone that they need to "charge to 82.467%" and need to monitor their usage using third party tools. I dont do either of those, and I have 22k miles on my 2018 model 3P that is simply "charged to 90% and left there" and my BMS range shows 274 (down from 279). My 100% charge shows 303 / 304.... while almost all of the people who "charge to 86.222333545%" break out their teslafi charts and have less than 300 miles showing on their BMS / range.

If the number bothers you, you dont have to switch to percentage (I dont, I have mine on miles because that makes more sense to me). Just stop managing it, plug in and set it to 90% and let your BMS actually balance your battery. That takes time, charging to 90% a "couple of times" wont balance it.

 

[jelloslug]

Why not try NOT "regularly charging to 80%", and just set it to 90% and leave it plugged in (especially now that we are sheltering in place). It may take a couple weeks of "leaving it at 90% and just plugging it in", but I would bet your "range comes Back" if you do that.

TMC has convinced everyone that they need to "charge to 82.467%" and need to monitor their usage using third party tools. I dont do either of those, and I have 22k miles on my 2018 model 3P that is simply "charged to 90% and left there" and my BMS range shows 274 (down from 279). My 100% charge shows 303 / 304.... while almost all of the people who "charge to 86.222333545%" break out their teslafi charts and have less than 300 miles showing on their BMS / range.

If the number bothers you, you dont have to switch to percentage (I dont, I have mine on miles because that makes more sense to me). Just stop managing it, plug in and set it to 90% and let your BMS actually balance your battery. That takes time, charging to 90% a "couple of times" wont balance it.

All of the 3rd party apps are just a complete waste of time. Even if they could give you some vaguely useful piece of information about the battery health, what are you going to do with it?

 

[rincewind]

I always charge to 90%, have now done 5k miles and the range is 309.5 miles @ 100%. Set it and forget it, it's never bothered me, I just enjoy the car. When I can drive it that is, which is hardly at all atm.

 

[bohenriksson]

Thanks all, that decides it: % 90 for everyday driving from now on it is and we’ll se what happens! After all that’s what Elon says... And he’s the one paying for all the warranty replacement batteries (should they be needed!)

Bo

 

[Need]

Thanks all, that decides it: % 90 for everyday driving from now on it is and we’ll se what happens! After all that’s what Elon says... And he’s the one paying for all the warranty replacement batteries (should they be needed!)
Bo

Unless there is something really off with your battery, you are not likely to see a warranty replacement. It needs to be under 70% of the original capacity to have a chance of getting it replace.. that means under 217 miles at 100% charge.

So far our MX and M3 batteries go down about 3% per year. So at the end of the 8 years warranty, I think they will both be above 70% from new.