Poor Battery Life on 85w Tesla Model S

Poor Battery Life on 85w Tesla Model S

Hi - has anyone else been experiencing poor battery life on the 85w Tesla Model S?

I've been driving my Tesla for nearly six months. It has been running at 350-400 W/mi, and generally only lasts about 120-150 miles. This seems to be unusually poor performance. I've asked Tesla in Dania Beach to look at it, which they have reluctantly done, but they have claimed it is normal. Then I nearly ran out of electricity on what should have been a routine trip to Miami, and was stranded until they arrived with a loaner that night. Disaster!

Tesla Dania Beach is still claiming it is totally normal, which boggles my mind.

Has anybody else has this problem?


AmpedRealtor | January 11, 2014

I've been driving my P85 in the Phoenix area since late August. I have about 4,500 miles. My lifetime average is 294 Wh/mi and dropping.

bb0tin | January 11, 2014

Maybe the owners suspecting battery problems could team up with an owner of a similar model who doesn't suspect problems. Meet up and fully charge both cars, check tyre pressure etc. Do a reasonable drive with one driver following the other. Swap cars, and who leads, for the return trip. Comparing the out/return kWh/mi will point to whether it is the vehicle or driver. It will also show up discrepencies in the reported range. And you get to meet up with another owner for a day out :-)

Brian H | January 12, 2014

That would detect whether one was afflicted with twitch-foot!

LazMan | January 12, 2014

There are so many factors affecting range. In the Canadian summer, my average energy use is well below rated. In the winter it is above.

One thing I noticed, is that last time I did a range charge, I had 419 rated km. I immediately started driving. It didn't tick down to 418km until I had driven about 10k. I did a total of 850 km that weekend with an average energy use of 173 Wh/km (about 278 Wh/mile).

I think part of the issue is that determining the amount of energy left in the battery is not so straight forward.

Also, the 19 tires are quite a bit better than the 21's.

abatra | February 2, 2014

I'm also having problems with my 40 battery. I used to wake up to 160 "ideal" miles. A few months later, it's 140 "ideal" miles and trending downwards. When I called to ask I was told someone would call me back to address my concerns. I never got a call back for many weeks. Ultimately I was told this is a manager related issue and that there are many others with the same complaint. Since our batteries are software limited, I couldn't see why they would not just adjust the software to increase the ideal mileage to 160 as it should be. I understand the rated miles could depend on my driving habits but the ideal range should remain at 160. I get the feeling Tesla is aware of this problem but is trying to avoid it. Agree with others that sweeping owners concerns under the carpet is not a wise strategy for the company.

Mel. | February 2, 2014

Thread is for discussing 85. Duh

bonaire | February 2, 2014

In a parallel/series battery system, if a couple cells in a "brick" are lost, that brick can show lower voltage earlier than the others, that can then lead to lower overall pack capacity, if the BMS can report a low voltage condition in this scenario, it can lead to a fixable condition. Can an SC look at a battery pack in this way?

Duffer | February 2, 2014

I've had my 85 for almost 11 months and put 16,935 miles on it. I did a 100% charge today and allow it to sit for another 2 hours plugged in. Range at full charge was 242 miles; a decrease of 8.67%. Not too shabby. Average wh/mile is around 320 - suburban Boston, so it's cold.

Pungoteague_Dave | February 2, 2014

@rdloftin, that doesn't seem too good... My car has more miles than yours, and consistently range charges between 267 and 272. It is actually higher than it was a few months ago after we ran it from full to empty every day for about ten straight days. The battery seems to like exercise in its full range. I never leave it fully charged, but do range charge once or twice per week to make a long commute between our homes.

David Trushin | February 2, 2014

I, also have had some battery concerns after 1 year and 11,000 miles. It's winter here and colder than last year, but my standard charge is less than for a 60. Also, the battery takes a long time to warm up even after heating the cabin. It often takes around 40 miles to warm up with continuous freeway driving. Then when i stop it cools down pretty quickly. As a result, my energy efficiency is quite poor. also, i don't get the battery cold message anymore. I asked the service center to look at it, but i think all they did was put a note on the service record to the effect that i needed to be educated. That the battery gets cold when it's cold out and that i should preheat the cabin because when i do that, the battery heater comes and conditions the battery. (Btw, i've been told previously by service that this is not true). I asked them how long it would take to condition the battery and they said about 15 minutes. Today, in 20 degrees, i preheated for 2.5 hours and the regen limit line moved fron 7 to 14, while the power restriction line stayed at 160. When i drove off, it took 15 miles to get full regen back. Then i stopped for 15 minutes and regen went to 45 and stayed there for the remaing 10 miles of the trip. I suspect there is a problem either in the battery cooling/warming system or some cells have droped out or both. But i think that service has been hearing so many complaints about winter perfomance that they've stopped listening. I'll eventually get it resolved with persistence.

Mathew98 | February 2, 2014

@David - Have you ever tried to schedule charging so it would finish just 15 to 30 minutes prior to your morning commute?

I've been doing so this whole winter and there's no limited regen or cold battery message in the morning. Assuming the car is charged in the garage, there's no need to use cabin preheating in the morning.

The return commute in the evening is another story. Cabin heating for 20+ minutes prior to departure will still result in limited regen. However, it is still better than no regen at all.

Give it a try and see for yourself...

David Trushin | February 3, 2014

Actually I have. It used to work. I'm going to do it today to see what's up

tezco | February 3, 2014

@David: I think the regen limits are now set more conservatively this winter, as compared to last.

Brian H | February 4, 2014

Cold batteries don't like to be recharged at high rates.

zwede | February 4, 2014

David Trushin wrote:

"Today, in 20 degrees, i preheated for 2.5 hours and the regen limit line moved fron 7 to 14, while the power restriction line stayed at 160. When i drove off, it took 15 miles to get full regen back."

David: Try setting the cabin heat to "hi" when you pre-heat. I've read that the battery is only heated in this setting, not if you set a target temp.

slipdrive | February 4, 2014

After 12K miles and August heat to this weeks subzero temps, this 85K battery pak is amazing me. Absolutely consistent, every day. Regen limits seem fine, and usually disappear after a few miles or minutes. Have seen no degradation in charge capacity whatsoever. One thing I noticed is that with the "slide" charge limit capability, it is a perception issue. In other words, the screen appears 80% but varies a bit each time set. So it goes from 199 range miles, to say 204 the next week after a weekend road trip and one range charge for example. After settling in with it, I am stunned at the technical aspects of this car, and the reliability and ability to use it. Wish I could say half that about the TV, phones, computers in the house....ha

David Trushin | February 4, 2014

Normally, i would agree with idea that it's cold and things are limited until the battery warms up. Except for 2 things:it consistently takes abot 40 miles to warm up, and i never get the battery cold message anymore. Makes me think that some of the software is thinking the battery is warm and some of it doesn't. But i'll try heating on hi. Btw, service has said in the past that heating the cabin does not heat the battery, but allows the cold heating cycle to work faster after you start driving.

p1SL | February 4, 2014

@David T: I have noticed that when in "range mode" I do not get the "Battery is warming" message. I think that the battery warms much slower in "range mode" as well as it seems to take longer to get regen braking back in cold weather. So are you in range mode?

David Trushin | February 4, 2014

Yes, I am. Thanks for the suggestion. I will switch it back and see if the behavior changes. I would have thought that the battery would heat faster in range mode. Is this documented somewhere?

Bighorn | February 4, 2014

Range mode definitely slows the warm up, both with climate and battery heating.

David Trushin | February 4, 2014

Today, I turned off range mode. The message came back. The battery appeared to warm more quickly, about 15-20 miles instead of 40. Also, I noticed that the energy usage was vastly improved. Before changing it, I was averaging around 400 wh/m over 30 miles, and after I turned it off, it was more like 335 wh/m. Silly me, I thought range mode meant "get more range" but it appears to be "eat more range"; at least in cold weather.

I haven't tried out the heating the cabin on hi suggestion yet. I deliberately did not charge the car to run the battery down. used about 53 Kwh since last charge and got about 135-140 miles with about a 30 mile average of 40 left. so that seems to be about what other people are seeing with the same weather conditions. Fortunately, it has been about 20 degrees F all three days.

Thanks for all the suggestions.

bevguy | February 4, 2014

I had a similar range problem once in an ICE. It turned out that the brakes had been adjusted too tight. I found this out when they caught fire on a highway trip.
Driving with your brakes on isn't good for mileage.

David Trushin | February 6, 2014

Ok, I think I understand what's going on here. First, heating the cabin on HI did heat the battery, while heating on anything else didn't. But only when the charge cable is plugged in. Thanks for the tip.

Second, I took it from Range mode to regular and the message popped up again. Also, the battery heated up pretty quickly for the the 20 degree temps we were having (I didn't preheat the battery for this trip). Also the energy efficiency was dramatically improved. In range mode with warm battery averaged 400, without range mode averaged 335. all on city streets.

My conclusion: Range mode doesn't appear to help in cold weather either before or after the battery warms up. Now I just have it in regular mode with the heater fan turned down and the temp comfortable and I'm happy. Thanks for all the help. More than I got from the service center.

mbirnie51 | February 6, 2014

In own a P85 and live in Seattle area, traveling 80+ miles per day. We are experiencing what is considered "cold" weather and I'm getting 210 miles on a rated 220 charge. My last 9.6K miles have an average 358W/mi, that's with 60% of my daily commute at 65mph and heat on, and 10+ mins "warming up" before I even get in the seat, in hilly terain. I will drain my battery 3 to 4 times a month down to 10 miles or less range before charging, and have not experience any degrading of battery life. I recently left Enumclaw Washington with a FULL charge(265 miles and assume 85Kwh), drove by the Centralia Super Charger (my wife thought I was crazy)and made it to the Woodburn Oregon Super Charger(200 miles per MapQuest), albeit I had 0 miles range for the last 10 miles(average speed 70mph) and my actual consumption was 76Kwh, yes..there is a reserve if you got the nerve! We did a full charge there and went on down to the San Fran area, and drove back to Seattle a few days later, using the Super Charger network all the way. I am approaching 15k miles in 6 months and have seen zero degrading of will always charge up to 220 rated miles(my setting), but I won't always get that in actual miles driven. The one thing you MUST keep in mind, range will always be effected by outside temperature, driving habits and terrain. I read with wonderment how some of you think you can drive at 80mph and expect your actual driven miles to be the rated miles.
I owned a Volt for 18 months putting 30K miles on it and only put 31 gals of (shudder) gas in it, so my range anxiety is pretty low. I am grateful that I can now ween myself entirely from the demon fossil fuel. Tesla is a great automobile, and will get better as the engineers fix some of the glitches

Brian H | February 8, 2014


Zero degradation is a great result. You're obviously doing some things right!

spunky | March 10, 2014

I'm also having battery issues on my 85W Model S. It seems I can't get anything above 250 mile charge when I need a full charge (270+) for a very occasional trip. Several calls to Tesla with no solution yet.
I've had the car over a year with just 5,000 miles.
Any comments/ideas?

ITSelectric | March 11, 2014

With temps hitting 50 here in Chicago for the first time since I've owned my S85 (12/17/13), I finally saw some amazing (for me at least) energy usage numbers...I drove 90 miles yesterday with an average of 304 Wh/m! I've been consistently in the upper 300s and mostly 400s. Can't wait to see the performance when it really warms up.

Mathew98 | March 11, 2014

@ITSelectric - Ditto the energy usage for my S60 in the high 40's.

A 20 degrees difference resulted in 25% drop in battery usage.

ITSelectric | March 11, 2014

I was white-knuckling it down to visit my daughter at college a few weeks ago...averaging 430+ all the way down at 70mph with temps around 5°F...rolled into town with just 24 miles left of rated range which I knew was really closer to 16. Luckily there's a supercharger right across the street from her dorm so 20 minutes later I had 100+ miles left and we had a nice visit. Stayed at the hotel across the street and left it on the supercharger all night and had 50 miles left when we got home with temps around 15°F. Looking forward to summer more than ever this year!

zwede | March 11, 2014

Temp makes a huge difference. Last month when it was -9C (15F) I drove to work and averaged 666 Wh/m. That was starting out in the garage that was at +11C. Now when it hits 20C in the afternoon (68F) I make the same trip at 320 Wh/m.

Mathew98 | March 11, 2014

@mstrobl2 - So a 53F degrees difference yielded 52% reduction in energy usage.

From our limited poll, it seems like the MS will incur roughly 1% energy usage increase for every degree (F) drop in temperature. At least from 15F to 68F...

zwede | March 11, 2014

Mathew: Yes, but keep in mind that my commute is short at only 7 miles each way, so there's a big energy penalty in heating the cabin & battery. I drove a bit further in cold weather and got 380 Wh/m.

Mathew98 | March 11, 2014

Well, my round trip commute is typically 50 - 70 miles each day. So the 25% reduction in battery usage when the temperature increased by 20 degrees is in line with your observations too.

Iowa92x | March 11, 2014

Math it out, 80,000 watts divided by 400 watts per mile equals 200 miles of range.