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Battery Degradation Question

Battery Degradation Question

I have an Sept 2014 S85. Ideal Range at that point, as you know, was 265 miles. At this point about >4.5 years and 49K miles, the max ideal range is 250. Is this something out of normal for battery degradation? I am trying to see if I should be asking for a battery replacement. Any input or help would be appreciated. Thanks and still grinning...

Bighorn | April 16, 2019

Ideal range was over 300, you are quoting rated range. 250 is not unusual and replacements based on degradation would probably have to be off >30%. Your at a little over 5%.

Bighorn | April 16, 2019

You’re

p.c.mcavoy | April 16, 2019

No, that’s not extreme degradation. Your talking 5-6%.

Also, no battery warranty on the MS for degradation. Only if there’s an actual failure of the pack.

Check out the Tesla MaxRange Battery Survey google doc. You can compare your car to about 400 other cars. You’re pretty well in the heart of the distribution.

p.c.mcavoy | April 16, 2019

Yeah, but BH said ... you’re, but I wouldn’t want to start another grammar thread.

aniketsaha | April 16, 2019

Great thanks guys. Your the best :-)

txakoli | April 16, 2019

My Sep 2014 S85 is at 50K miles, 100% charge is now 252 RM. It’s pretty close to the degradation trendline shown in the google doc mentioned by p.c.

eggbert747 | April 16, 2019

My 2014 @ 60K is 256 max RM. Can vary 2-3 miles either way. I'm happy since it's been holding steady the last year.

donnan56 | April 17, 2019

My 2017 S75D @ 38K miles, 100% charge is now 238 RM vs. 259 RM at new. Its 9% degradation after a little over 2 years. Is it normal rate and should I file a complaint to Tesla ?

pastorjimkuchera | April 17, 2019

My S is a May 2014 car with 89K on it. Was 265 miles state of charge the day I received it, May 23, 2014, and 100% charged it last night at 30a, rather than the common 40a. This morning in a heated garage and 70 degrees, the 100% charge was 257 miles. That number has remained constant over the last 25K miles. I find this much more than acceptable. Tesla will only replace a module, or pack, if there is a complete failure. Modules do fail, and formerly the pack went back to Tesla for repair. The policy now is that you receive a refurbished pack if yours is beyond help. I waited a year for my original pack to be repaired and returned. Perhaps that is why my pack has sustained such a fine state of charge over the last three of five years.

Yodrak. | April 17, 2019

"was 265 miles. ... is 250"
"Was 265 miles ... the day I received it, ... This morning ... the 100% charge was 257 miles."

Tell me, is the 15 or 8 lost miles cramping your style? Preventing you from using the car as you'd like to use it?

thomaslee731 | April 21, 2019

My Delivery was on 12/10/2017, 259 mi out of 259 mi
12/01/2018, 249 mi out of 259 mi
4/21/2019, 239 mi out of 259 mi
Something is not right, I was told wait till it drops 40mi, then it is abnormal.

jordanrichard | April 22, 2019

thomaslee731, who told you to wait until it drops to 40 miles?

Also, what is your typical SOC usage? Meaning, do your charge to say 80%, then only run it down to 75% on a daily basis? If so, then your issue may very well be the algorithms going wonky. You need to think of your battery as a rubber band. If you constantly just stretch it to "x" amount, you start to forget how much it can stretch. Run the battery down to about 10% and then charge back up to 90-100%. Do that a couple of times, then see what your displayed Rated miles are.

Lastly, temperature affects, albeit to a small degree, the displayed Rated Miles. In other words, 90% in the winter will be different than 90% in the summer. If you are going to track things, in an effort to spot a problem, you need to be consistent on when you are making note of stats.

TMS | April 22, 2019

@donnan56, thomaslee731 - For reference on the S75D, I charge to 235/236 @100% SoC since roughly 25K miles. My vehicle is approximately two years old and I have added 3K since and charge to 100% about quarterly during road trips after bringing the SoC down to the very low single digits. I think the initial range was over advertised and I never saw 259 at any point in the past. I think our degradation should be measured from 250-252 which I have directly observed and which is approximately a 6% reduction in range. Should it stay consistent at this point, I will not be overly concerned. I think the problem is trying to incorporate Tesla’s approximately 3% optimistic addition to the vehicle initial rated range. My typical charging pattern is within 10-90% with virtually no variation and I do not charge often back up from the middle of the range. My charging is split between Home <==> Superchargers roughly evenly and somewhat to the right of the arrow.

kerryglittle | April 24, 2019

Slow charging at home is the best for your long term battery life.

jordanrichard | April 24, 2019

"Slow charging at home is the best for your long term battery life". Yes however that is not say that supercharging a often is bad. Running the battery low, then Supercharging to full and then run it down to empty and repeat on a daily basis will cook your battery. The pack needs time to rest.

AERODYNE | April 24, 2019

All;

This has been beat to death here and elsewhere.

The following only applies to the 2014 and up S and X with 18650 cells and no known pack issues.

Most people, most of the time, SC will not be done enough to make battery degradation an issue. Even with free SC, and a SC station right off your daily commute, how much is your free time worth? If it is more than say, $10 /hr how would that make sense when you could charge at home, and wake up to just the right charge level needed for today?

Case in point, I have used less than 600 worth of elect in 6 months and 8k miles. Depreciation, insurance and maintenance in that period is TWENTY times that.

If you are one of those rare folks that must SC often, just charge what you need, 50-90%. Anything over that, drive away soon after charging to 90% or less.

If you can't help but obsess over the Batt, like I do, then keep the SOC at 50-62% when possible. I have LESS than 0.5% degradation after 4 yrs, and am exploring ways to keep it there. Retired and nothing else better to do, DW reminds me.

TeslaTap.com | April 24, 2019

If it's helpful, I created this chart on all versions of the S/X/3 with the estimated of range at 60K miles and 120K miles. https://teslatap.com/articles/selecting-the-right-battery-size/

If you're within +/- 10 miles of these numbers, I'd consider it normal. If you suddenly drop by 6%, one of the modules has failed and is covered under warranty.

The table was updated today with the new S/X versions too.