Battery life

I use my car a lot. About 30,000 miles per year. Can anyone tell me what the battery life expectancy is? If I have, say 100,000 miles on the battery, what kind of range will the battery have left? 90% of my travels are under 225 miles and that's why I ordered a S with the biggest battery. But, if the battery is rated at 265 miles and at 100,000 miles it only has, say 70% capacity left, that puts the range at about 185 miles. That just won't work for me. Also, does anyone know what Tesla's policy is on battery replacement. Will they replace the battery if it's under 80% capacity? 70%? 60%? or what? Thanks.

The following thread over at TMC has a lot of related discussion:

Seems like the replacement policy might work for you. Warranty would only cover flaws, not normal degradation.

As a side note, the "safety margin" TM appears to have allowed itself is about 100%, which is to say the stated decline rate is about double what they actually expect (and have considerable Roadster experience to draw on).

On the other hand, if you are routinely charging to a range of 265 miles (rated), your battery will degrade faster. TM recommends that you use a "standard" charge rather than a "range" charge on a regular basis. A standard charge will give you 230-240 rated miles.

Thanks all. But, an 8 year replacement battery option still puts me at 240,000 +/- miles. I still don't know what kind of range or battery capacity I will have at 240K....or 100k...etc.

I read somewhere that charging the battery quickly shortens battery life. Does anybody know if this is true? If so, would it be advisable to avoid the high powered wall connector (and twin chargers) if I don't need them? Would just sticking with a 240 volt outlet in my garage be a way of maximizing battery life if I don't think I need the quicker charges?

@paulehardy - Nissan says fast-charging the LEAF once per day (close to the charge rate of the Supercharger) won't degrade the battery, but they don't recommend more than that. I believe Tesla has said that charging via the HPWC doesn't impact the battery longevity -- for the Superchargers, there have been conflicting reports, but I believe you can charge as often as you want at those and it just slows down charging over 50% to protect the battery. I think the bigger issue is repeatedly charging to 100% (max range mode).

I'm getting dual chargers and the HPWC even though I plan to normally charge at 50A (so I can also charge the LEAF at the same time) -- that way I will have the option to charge at 80A if I need to.

If I recall correctly at the supercharger opening ceremony Elon said the Superchargers will not damage the battery.

Spoke to a Tesla rep today who said Supercharging is harder on the battery than normal charging and would only recommend it for road trips as opposed to an all-the-time thing.


I'm happy to see your post. Sound very similar to my life, driving about 650 weekly...165 daily on some 3-4 days each. I worry a little but suspect there should be no issue even with degradation but I am concerned about winters in Illinois and the day-drain. I am working on convincing e building to contact Chargepoint to set something up but I don't know how much charge we get from a J-1772 either. It's all new to me.

I hope e "300" or "EPA 265" range is real and We don't have to worry, ever.


@drpeggau - I just posted this elsewhere but thought it useful to post here - I just did the first freeway run in my performance S and averaged 360-370 Wh/m with cruise control at 80mph with A/C on and two people in the car on a flat (South Florida) I-95. That equates to c.225 miles with a Range charge. Better than I expected.


I suggest you consider Cliipper Creek instead of Charge point. charge point is 30amps max (roughly 20 mph charging). Not very useful for a Tesla.


I had a very long conversation with a manager at the Tesla store in Oak Brook Illinois yesterday. He indicated that the battery likes to be charged at a slower rate rather than a faster rate in terms of limiting degradation. He said that I really would not need a home charger or HPWC but would be best off using the NEMA 14 – 50. Most of the time the car would have at least eight or nine hours to charge anyway. He suggested driving the vehicle in range mode with the displays set off And this would limit the drain on the battery while it is parked. He indicated using units/format "rated" which monitors how I'm driving. He also indicated that I would probably have to charge to max range most of the time.


I as I am waiting for my opportunity to acquire said vehicle - I find reading about everyone's experiences to be really helpful (if not a little concerning).

Based on what I've seen here, people are getting about 70-75% of the rated miles. Given that Tesla states that after 7 years battery capacity will have dropped by 70%, your range will be significantly curtailed.

I am really looking at this, as my daily commute is about 135 miles per day. With the above info, at about 6 years I no longer will be able to make it back and forth to work...

The replacement plan only kicks in after the 8th year - suggesting that there would be 2 years that I couldn't use my car (and at this price, that would be totally unacceptable).

Am I off base here? Did I screw up the math? Leasing would be an unlikely option as I drive too much. And I would take at least that long to pay it off..

Have been looking into range impacts due to cold weather and battery age on Tesla Model S. Trying to decide if I need to step up one battery level to support year round driving and driving as battery ages. Information I've seen indicates I should allow for a 20% range impact as result of cold weather (though suppose for extreme cold might be worse). With Volt and Leaf apparently range impact as result of cold can be 40%. Also concerned with impact to range resulting when car is parked at work location for 8 hours in cold.

Not enough of an engineer to know how Direct Current Internal Resistance (DC-IR) and capacity might together impact range (effective capacity) but with my limited engineering skills this article leads me to believe that under "normal" weather conditions one might expect battery capacity to be 90-100% of original capacity after 8 years of service.

Believe the article studies the individual Panasonic Cell that Tesla integrates into the Model S battery pack.

100 200 300 Storage periode /days
Fig.1 Storage characteristics of tested cells. Closed and open symbols indicate stored SOC of 90 and 30%, respectively. Circles and triangles indicate stored temperatures of 25 and 60°C, respectively. The vertical axis indicates the change ratio in discharge capacity or DC-IR with respect to the initial value.
Fig.2 Charge/discharge cycle characteristics of tested cells. Cycle tests were performed in voltage range of 3.60 to 4.05V. Closed and open symbols indicate operated current rates of 2 and 1It, respectively. Circles and triangles indicate ambient temperatures of 25 and 50 °C , respectively. The vertical axis indicates the change ratio in discharge capacity or DC-IR with respect to the initial value.
1000 2000 3000 Cycle number /-
● SOC90% 25°C ▲ SOC90% 60°C ○ SOC30% 25°C △ SOC30% 60°C
●2It 25°C ▲2It 50°C ○1It 25°C △1It 50°C

Development of High power and Long life Lithium secondary batteries
Shoichiro Watanabe, Takashi Hosokawa,
Ken’ichi Morigaki, Kensuke Nakura and Munehisa Ikoma
Panasonic Corporation, Energy Company Technology Development Center
1-1 Matsushita-cho, Moriguchi City, Osaka 570-8511, Japan

The chart supported no more than 20% loss. Hard to believe

Anyone with current and applicable engineering and or science skills care to interpret the paper? Looks like 90% to me 3000 cycles working out to about 8.5 years if you figure one cycle per day.

drp you see "no more than" 20% ..., we were posting at same time!

Ahh I see your 20% if you figure extreme heat conditions.
I'm not going to see that kind of heat!

I've seen information that leads one to believe that, with respect to battery life, Lithium-Ion "likes" being stored in cold ..., in that it can/will extend battery life. Suppose that may be why study covered the temp range it did ..., might be more problematic for battery cell.
25C <=> 77F
50C <=> 122F


With careful driving, you can get pretty close to rated range. Very cold weather, hills, heavy use of accessories, and most of all, speed will reduce that range considerably. However, I think you will be able to get 135 miles on an 85 kWh battery for a long time, certainly eight years. Besides, isn't it likely that in a few years there will be places to charge up at work and along your route?


I'll admit it, I'm like Sammy Haggar... I can't drive 55 :}

Where I live it's not to bad on the hills and while we have 4 seasons, it's not really been that harsh (nothing like the UP in Michigan).

There is a snow-ball chance in hell that charging stations will be placed near where I work. We are (and have for years) had significant issues with managing power and cooling requirements -- and that isn't going to change soon.

I hope you are right... I generally keep cars for a long time (my last two 10, 9+ years) and I NEVER have any considered spending this much for a car. So, I would like to have it for longer than it would take to payoff.

wonder and drp:

Be a little careful about the date in the ECS abstract. I am not sure the Panasonic cell that they tested had the same positive electrode composition as the cell used in the Model S. There is a good possibility that the Model S positive electrode contains a good percentage of manganese. I am extremely familiar with the chemistry of the cell studied. The variations in its performance are driver by the positive electrode, hence the concern with using these data to access the Model S battery.

The data do, however, give a very good feel for how you should tread your battery; ventilate the garage and delay recharge as long as possible (this should become easy once the new new software version is released.

By the way, cells tested and the Model S cell do behave similarly. About five years ago I developed a heuristic model for the tested chemistry. I have applied this program to my Model S and example of its prediction with a 60 mile daily round trip is a life greater than 20 years.

"delay recharge as long as possible.."
What do you mean by this? Let the battery get low before recharging?
Tesla states "The Tesla battery is optimized for nightly charging: topping off frequently enhances the longevity of your battery."


I drive @ 165 miles daily 3-4 days a week and it will sit for 6-7 hours. What does the heuristic model suggest I do to make the battery last a meer 10 years for such a daily commute, expressway, 65 mph with normal interior climate and a radio on? Any suggestions or insights would be tremendously appreciated.

I have found the heater makes a huge difference -- I got my car on Sunday, and early in the week it was around 40 degF. I was getting about 380 Wh/mi, which was a lot higher than I expected. The last couple of days have been in the 60s, and I have actually been averaging around 320 Wh/mi (and for non-highway sections, getting well above the rated miles calculation).

I think he means to have the car finish its charge cycle when you are ready to use it. You don't want to get home from work plug the car into the HPWC and fully charge the car in four hours just to have it sit there overnight. The battery is not very comfortable at full charge but, full charge is just what you need before setting out. What ever you plug the car into, you should limit the charging current so that the car will be ready just when you need it.

From the owners manual:

Your Model S Battery is one of the most sophisticated battery systems
in the world. The most important way to preserve the Battery is to LEAVE YOUR MODEL S PLUGGED IN when you’re not using it. This
is particularly important if you are not planning to drive your Model S for several weeks. When plugged in, the Model S wakes up when needed to automatically maintain a charge level that maximizes the lifetime of the Battery.

A cycle refers to a full charge from empty; two 50% charges are just one cycle. One cycle a day seems like a lot; pushing the car to its limits every day from day one.


Yep, I agree completely with your view above. I'm expecting delivery in March/April (60 kwh, Air). #9965

I'll only rarely do "range" charges, but when I do, I'll immediately start driving in order to drastically limit the amount of time my battery is ever at 100% charge. Likewise, I'll hardly ever run my battery down to nearly empty and I'll begin charging ASAP.

My normal nightly plan during the work week is begin charging after midnight and have the standard charging finish right before I leave for my morning commute. I only have a 30 mi round trip so many days I can probably start charging around 5am. I'm also considering not charging at all some days. I'd like to see more analysis on the lifespan benefits of having the battery below an 85% SOC most of the time.