Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[NemezisGB]

Thanks AlanSubie4Life, thats exactly the answers/confirmation i was looking for regarding 75 vs 77,8 kWh and "buffer".

All capacity loss is relative to that (the 2.8kWh "buffer" doesn't give you a "buffer" against capacity loss; there is a portion of the battery which will never be accessible to you which scales in proportion to the capacity loss).

Do we know that they will never release that buffer/softlock of 2.8 kWh? Could it be unlocked via third-party software like ingenext?

Also: Does the extra 2.8 kWh buffer protect against high SoC degradation? e.g. a SoC of 90% would in reality be lower than an actual 90% of the battery capacity and thus be a "healthier" SoC compared to a battery that had just 75 kWh capacity.

 

[stevesark]

I remember reading on this site a long time back that if you set your charge limit to say 90%, car's display says you used 10 KwH since last charge, you recharge to starting point should be about 10 KwH. My car will regularly take 16 KwH in actual energy before hitting 90% in above scenario.

Not worried about it per se, just curious why.

 

[jjrandorin]

I remember reading on this site a long time back that if you set your charge limit to say 90%, car's display says you used 10 KwH since last charge, you recharge to starting point should be about 10 KwH. My car will regularly take 16 KwH in actual energy before hitting 90% in above scenario.

Not worried about it per se, just curious why.

I dont think I have ever seen anyone say that, but I also dont deep dive into all the various battery threads. I am fairly certain that the car display "used since last charge" does not account for energy used when not driving.

 

[AlanSubie4Life]

I remember reading on this site a long time back that if you set your charge limit to say 90%, car's display says you used 10 KwH since last charge, you recharge to starting point should be about 10 KwH. My car will regularly take 16 KwH in actual energy before hitting 90% in above scenario.

Not worried about it per se, just curious why.

No, this is not correct. Aside from the losses not shown which occur when the car is in Park, the energy added also includes AC-DC conversion losses, which of course are not displayed on the meter.

 

[stevesark]

No, this is not correct. Aside from the losses not shown which occur when the car is in Park, the energy added also includes AC-DC conversion losses, which of course are not displayed on the meter.

So these two added being 50% over car reading is normal for park plus conversion loss?

 

[AlanSubie4Life]

So these two added being 50% over car reading is normal for park plus conversion loss?

Yes, depends on the interval in question, but quite normal. Unfortunately.

1.4 is a good factor to use for cold climates, 1.3 for warmer. So 1.5 would not be uncommon at all.

 

[Godlike23]

Does anyone know how reliable the battery percentage display is? I have the M3 Long Range model and I have driven nearly 20K miles (2 years old). I usually try to keep the car 90% charged. I'm trying to get a rough sense whether or not my car battery is experiencing an abnormal level of degradation. I recently began to track the battery usage percentage in relations to the amount of KWH used. I noticed that for every 20% battery usage, I burn about 12 KWH (i got this number from the console where it said "usage since last charge"). This implies my battery maximum capacity is now at 60KWH (12/0.20) compared to advertised LR model of 75KWH. Did the battery really degrade that much in 2 years?

 

[haroldo]

Watch this

Short answer, it's normal, most likely related to weather, probably not worth worrying about, since, at best, range is an approximation.
Unless one is regularly traveling long distances, most don't need the full range (the average person drives under 40 miles a day).
If there's a catastrophic drop off in range, contact service, otherwise, don't worry about it.

 

[Henderson18M3P]

I'm brand new here. Bought 2018 Model 3 Performance six months ago. 42,000 miles, seemed to be in perfect condition.

Most of what I'm reading in this forum is about estimated range getting lower under whatever circumstances. My issue is different I think. Yesterday I supercharged my M3P to 90% as usual. The estimated range at 90% was 251 miles. BUT! I drove it 150 miles and remaining capacity was 10% and estimated remaining mileage was 25 miles. This doesn't seem like an estimated range issue -- it seems like a "will only give you about 60% of estimated range" issue. I may have had this gap since I bought the car although I was so new to Tesla I maybe didn't recognize it.

I've never set up Summon. I don't use Sentry Mode. I have the appropriate settings on "Sport" rather than Chill. I have regenerative braking set to the more aggressive setting (I can't get to the car at the moment to get all the setting names right).

Is this merely a calibration issue? If so I'm certainly willing to take appropriate action. Could this be a battery defect issue? If so, how should I proceed?

 

[Sophias_dad]

Obvious questions:

Was the heat on? Were those 150 miles in one continuous trip, or over several days?

How fast were those 150 miles traversed? Power to overcome aerodynamic drag goes up with the cube of speed. Increasing speed by 20% increases power usage by 72%. As an example, 78mph instead of 65mph is exactly 20%. (The actual drag goes up with the square of speed, but since more work is being done, power is the cube of speed).

Since you are in NH, was your elevation going up in those 150 miles? It takes a decent chunk of power to lift 4000lbs up a mountain.

 

[ATPMSD]

Remember the range is based on the car being driven at a specific wH/mi consumption rate. Look on the energy screen, the straight line from left to right is this consumption rate.

 

[CDennis100]

Remember the range is based on the car being driven at a specific wH/mi consumption rate. Look on the energy screen, the straight line from left to right is this consumption rate.

Colder weather….YMMV. Try that same jaunt in the summer and you’ll then get what you expect.

 

[Sophias_dad]

Don't forget tire pressure. 42psi minimum, although earlier 3's had a tire placard saying 45psi. These are cold (car not driven overnight) pressures.

 

[mswlogo]

If you are down to 251 miles at 90% that is some serious degradation to start with. Maybe something is wrong with the battery.

What wheels are you running? Hope you are not running the OEM 20” in NH.

 

[Henderson18M3P]

Some additional information:
* I live in NH but I am in Florida now, where the 150 mile trip was taken.
* The 150 miles were driven all at one time. At least 2/3 of the drive was on rural, two-lane roads with relatively low speed limits which I did not, for the most part, exceed. The other 1/3 was Interstate, where I probably didn't exceed 85mph.
* Being in Florida, running the heater was not a factor. Elevation was not a factor either.
* My tire pressure is 42psi.
* I cannot access the car right now and I do not know what wheels I have, but if type of wheel was an issue only related to driving in the snow then it's not that.

My utterly uninformed assumption is that I have some sort of battery defect. If that turns out to be the case, I think I read elsewhere in these forums that Tesla can check your battery over the Internet. Would that be possible in this case?

Thanks so much for all the input.

 

[mswlogo]

You might have a battery defect. But 85mph will cut down your range pretty fast.

Alignment issues can chew up battery and tires too.

How long have you owned it? If you are lead footing it, that will chew up range fast too.

 

[Unclepaul]

If OP has set a reserve of 10-20% is range is not all that far off.

Range can vary greatly, mostly due to elevation changes, speed, wind, tire pressure etc.

 

[Big Dog]

If you are down to 251 miles at 90% that is some serious degradation to start with. Maybe something is wrong with the battery.

The original production cars are coming up on 4 years old. My April-18 delivery is charging to 253 at ~90%.

 

[mswlogo]

The original production cars are coming up on 4 years old. My April-18 delivery is charging to 253 at ~90%.

My Sept-18 3 lost 2 miles in 1 year 10K miles
My Sept-19 X lost 2 miles in 2.5 years 27K miles

What are you doing to your cars. First year losses are supposed to be the highest too.

 

[jjrandorin]

My Sept-18 3 lost 2 miles in 1 year 10K miles
My Sept-19 X lost 2 miles in 2.5 years 27K miles

What are you doing to your cars. First year losses are supposed to be the highest too.

Your model 3 result is not "the norm" in any way. "The norm" from reports throughout this giant thread and elsewhere, is somewhere around 6-10% degradation on a model 3 the first year. what any S or X had as far as degradation has not proven to be relevant in the slightest as far as model 3s.

My Dec 2018 Model 3 P is 260 at 90%. Remember that tesla revised the rated range on Model 3 Performance vehicles with the stock 20s down to 299. If 100% is 299, and 90% is 251, I believe that means their current 100% should be around 278/279, which is about 8%, well within the normal range of battery degradation.

So, @Henderson18M3P sounds like they have 8-9% battery degradation on a 2018 model 3P which is a quite good result. As far as the "I only got X miles driving Y distance, and part of that was driven at 85MPH, well.... shrug.