Battery Range - Performance in the Real World

Battery Range - Performance in the Real World

I need some help/input from the “Forum.” Perhaps Roadster owners can advise me from their hands on experience. I am trying to decide between the 160 or 230 mile range battery.

1. Am I correct, the Roadster and ‘S’ batteries are roughly the same?
2. The factory uses the 245 mile range for the Roadster. What is your real world mileage range in daily driving?
3. After a couple of years what percentage decrease in range and performance have you experienced?

Also, I understand the faster I drive and the more accessories I use will reduce the range. I am not a racer but I do enjoy a spirited drive. I will likely have the air conditioner or heater, audio, and other accessories on. The 160 range battery will satisfy 80% of my daily driving needs but if the real world range and age degrade the actual range to under 120, I may need to step up to the 230.

Thanks for your help.

Mycroft | 04. November 2011

If you need to regularly drive more than 100 miles on a single charge, then I would highly recommend stepping up to the 230 mile pack. The standard daily charge will most likely normally top out at 80% or so of the battery capacity for longevity reasons. When the battery is "maxed out", a little more damage is caused each time. So you wouldn't want to do it every day.

While 80% of 160 is about 125 miles, I would want a bit more elbow room to allow for future degradation.

Larry Chanin | 04. November 2011


This article is very informative.

Roadster Efficiency and Range

In particular check out this graph to see what your ideal range will be at various speeds.


Larry Chanin | 04. November 2011

So using the above graph and assuming the Model S battery is similiar you can calculate the ratio increase or decrease over the EPA range of 245 miles and multiple it by the proposed Model S ideal battery range.


EricK | 04. November 2011


I read in this forum that roadster owners typically charge only to 80% to prolong the battery life. That said, I drive mostly freeways, UGH! the range really drops off. I was confident with 230 miles, but given that I drive all freeways daily 110 miles, I may have to go up to the 300.

Roadster Reference
Avg SP 245 100%
60 220 90%
65 200 82%
70 180 73%
75 170 69%

Model S Miles same avg speeds
Charged at 100% Charged at 80%
160 230 300 160 230 300

144 207 269 115 165 216
117 169 220 94 135 176
86 124 162 69 99 129
60 86 112 48 69 90

Thanks for the info. Eric

EricK | 04. November 2011

Better table
Charged at 100%
Avg SP 160 230 300
60 144 207 269
65 117 169 220
70 86 124 162
75 60 86 112

Charged at 80%
Avg SP 160 230 300
60 115 165 216
65 94 135 176
70 69 99 129
75 48 69 90

qcarl | 04. November 2011

So with a 300 mile pack, the drive from SF-LA and back is going to be a bit more difficult than expected, requiring more than just one charge stop. Who drives less than 75mph on I5?

EricK | 04. November 2011

Well Not really. At an average speed of 75 MPH, you can go a max (100% charged) of 112 Miles. If you charge the battery to 80% and at avg speed of 75mph you will go 90 miles. For me it is ~380 miles from my house in the bay area to LA. Likely use another car for those trips.

I hop I am wrong! - E

cerjor | 04. November 2011

I am willing to drive 60 mph on an annual back and forth trip between Seattle and Phoenix (1600 miles). I figure I'll go 200 miles in the morning, charge in the afternoon, and drive another 200 miles before ending the day. That makes it a four day trip. Do you think I will make it?

EricK | 04. November 2011

I think it depends on where you charge. Below is rough and was based on a response to a question I asked earlier today. Assumes a 10% conversion loss

Charging to 100% of capacity

Rate 300 Miles
Volts Amps Rate kWh 90 kWh
110 15 1,650 1.65 60.6

220 30 6,600 6.6 15.2

440 50 22,000 22 4.5

Charging to 80% of capacity

Rate 300 Miles
Volts Amps Rate kWh 72 kWh
110 15 1,650 1.65 48.5

220 30 6,600 6.6 12.1

440 50 22,000 22 3.6

Miles gained for each hour of charging

Volts 110 220 440
Amps 15 30 50
4.95 19.8 66

EricK | 04. November 2011

Sorry I have not figured out how to format. Charging to 100% for a 300 Mile (90 KwH) battery will take 60 hours if you use a standard wall outlet 110 volts 15 amps. This declines if you use a dryer outlet at 220 volts and 30 amps to 15.2 hours.

Lastly, if you can find 440 volts and 50 amps to charge from - every hour of charging you can go 66 miles

Robert.Boston | 04. November 2011

EricK, I think you made math error somewhere along the way. If driving at 75mph drops the effective range by 69%, as per your table, then the 300-mile battery goes 208 miles, not 112 miles. I think this table is correct, assuming that the Model S has the same performance curve as the Roadster:

100% Charge:

&nbsp&nbsp&nbspModel S Battery Range

Note that, because the Model S apparently has a Cd of 0.22, much better than the Roadster, it's possible that the curve will be better.

Robert.Boston | 04. November 2011

(the partial implementation of HTML on these boards is annoying)

BruceR | 04. November 2011

Thanks Robert, I think your chart is closer to what we can expect. I would also note that while the Cd is significantly lower, the A is significantly higher. What this means is that it should be a wash (CdA product is nearly identical then for the two cars.)and the charts that apply to the roadster can almost directly be used for the 230 mile pack Model S....

EricK | 04. November 2011


THANK YOU! You are correct. What a relief. Do you buy into the charge to 80% to extend the battery life?

William13 | 04. November 2011

Mycroft is right. You should not give a complete charge or discharge as this degrades the battery a little each time.

Robert.Boston | 05. November 2011

Agreed, William13; but even on Range mode, the battery isn't completely discharged (or even completely charged -- it could be pushed). But it's clear that Range mode should be used only when needed.

Volker.Berlin | 05. November 2011

(the partial implementation of HTML on these boards is annoying) (Robert.Boston)

Maybe it's your partial HTML syntax... ;-) Try " " (do not forget the semicolon).

Volker.Berlin | 05. November 2011

Note that, because the Model S apparently has a Cd of 0.22, much better than the Roadster, it's possible that the curve will be better. (Robert.Boston)

From the information we have so far, it seems fair to assume that the better Cd will almost precisely be canceled out by the larger A(rea). Timo has made the following calculation in another thread:

Roadster Cd is pretty bad actually. Something like 0.35 according to wikipedia, so 0.225/0.35 = 0.643 (rounded) gives a rough figure how much bigger the front area can be to get same result.

(roughly, not counting tires)
Model S dimensions = 1426mm * (2189mm - 154mm) = 2.9 m^2
Roadster dimensions = 1851 mm * (1127 mm - 130 mm) = 1.85 m^2

1.85/2.9 = 0.64.

That's d*mn close to counter the larger area pretty exactly.

This means you can actually use the Roadster table for Model S air drag in "Roadster Efficiency and Range".
(Timo in

Robert.Boston | 05. November 2011

Larry Chanin did a better chart on mileage, posted here:

Larry Chanin | 05. November 2011

Hi Robert,

I wouldn't say that it was better. I did steal your chart layout though. ;-)


Zelaza | 06. November 2011

Until such time that charging stations are readily available and can provide a very fast charge, it is fair to say that range should be the distance you can go and return home; that is, half the total distance that the BEV can go on a charge when you start. In the several useful tables provided in this thread, thus far, the "range" numbers should be halved if this definition of range is considered. As to how ling it will take to have a sufficient number charging stations, I have no idea. But at least ten years from now would not seem unreasonable.

EdG | 06. November 2011

@Zelaza: I agree, unless you're headed to a hotel/motel with a charging station acknowledged in advance.

Otherwise you're thinking like Chico Marx: tried to fly across the ocean, got halfway there, ran out of gas, had to go back... etc.

The Froq | 06. November 2011

Positive as always! If you don't like EV what are you doing here?

brianman | 06. November 2011

They aren't describing it as boomerang-range. It's pure, simple range. So, no, it shouldn't be halved.
transportation distance traveled without refueling: the farthest distance that a vehicle or aircraft can travel without needing to refuel
the distance that can be covered by an aircraft, ship, or other vehicle, carrying a normal load without refueling.
b: the maximum distance a vehicle or craft can travel without refueling

Even for aircraft direction discussion...
We generally consider the range to be the distance the
aircraft can fly from a given speed and altitude until it runs out of fuel

brianman | 06. November 2011


My5bAby | 06. November 2011

With all due respect, Zelaza is obviously an oil industry plant and should be ignored.

1. Unless you have a very unique job most people work a minimum of 8 hours a day.
2. My employer and most imployers would be willing to dedicate a space and an outlet for one employee who has an EV.
3. 10 years from now when there are greater than 100 thousand EV's on the road infrastructure will become increasingly important.
4. If you download the app recargo it will be obvious that infrastructure is actually ahead of demand.
5. EVERYONE/EVERY STRUCTURE has a110v outlet and many have a 220v outlet
(for example my office has a 220v that previously was used for an air conditioner & I will be using it)

8 hours on 220v will totally charge even the 300 mile battery.

One year ago I purchased a nice used vehicle for road trips. The more I learn about the Model S and think this process through, the more I realize that I will even be able to use my Model S for road trips as well.

Don't be fooled or swayed by Zelaxa or an industry that;
A. Dismantled the existing public transit system (trolleys) that we are now reinstituting as (light rail)
B. Said mandates to include everything from turning signals, seat belts, air bags etc would destroy the industry and make cars unaffordable.
C. Successfully lobbied against 55mph speed limit which both saved lives as well as TOO MUCH GAS.
D. Successfully lobbied and kept trucks from being included in CAFE standards then convinced a significant number of us to pay more for them because of minimal updates to the interior, furthermore convinced us that only driving in something the size of a hummer would keep us and our children safe.
E. Bult an electric car but would not let us buy them, then took them back and destroyed them.

My fellow Tesla / EV enthusiasts, the oil and automobile industry are scared !

Zelaxa, how much are they paying you? Should be at least $100 per post. If not you should renegotiate.




People wake up, it's not that difficult.

Signature 482

My5bAby | 06. November 2011

Referencing C. Above for clarification

55mph speed limit saved lives and saved TOO MUCH GAS. There was a significant drop in the amount of gasoline being used and the Oil Industry did not like this.

brianman | 06. November 2011

"55mph speed limit saved lives"

That was the premise. But my recollection is that newer information (last 10 years) proved the opposite. I believe it was something related to improvements in vehicle quality at higher speeds.

brianman | 06. November 2011

May 31, 1999
"All of the evidence thus far indicates that Americans have not responded to higher speed limits by converting the highways into stretches of the Indianapolis 500. Any loss of life has been very minimal—and at most a tiny fraction of what had been predicted by the safety lobby. Meanwhile, Americans have saved some 200 million manhours in terms of less time spent on the road. The net economic benefit of raising the speed limit has been between $2 and $3 billion a year."

Towman26 | 06. November 2011

So we dont travel much but my wifes surgeon is in Tampa which is 196 mile one way, the other place we always excape to is Disney, which is 130 mile away. So we definatly need the 300 mile battery and I better slow down, in my MB S550 we usually do 80-90 cause you really dont realize your going that fast. Here in FLA we dont have any charging stations yet but I know Orlando & Miami are working on putting some in which will be great once more EVs get on the road.

We own a towing company & I am wondering if Tesla has taken the "Our cars dont break down" idea like some car makers. I need to see if they put provisions for me to put them on the flatbed. When BMW changed there body style a couple years ago they didnt have the hooks we have now for part of the year, but then somebody told them & they fixed it. It would be great if they have the eyelt behind the bumper with the removable peice to hide it but none of the pictures Ive seen show it. Since Ive already had to tow my wifes S550 for running out of gas Im positive I will have to get her for not charging the Tesla LOL

My5bAby | 06. November 2011

Was not arguing for the 55mph speed limit, just recalling the episode/era

Signature 482

brianman | 06. November 2011


Well you didn't make an argument for it, but you made an biased assertion which turned out to be incorrect. If you would have stopped with "Successfully lobbied against 55mph speed limit" then I wouldn't have said anything. :)

Robert.Boston | 06. November 2011

I think you're all vilifying Zelaza unfairly. He made a correctly qualified statement: if you don't have a place to recharge, your effective driving distance is halved. He's right. The question is what are the "places to recharge"? And here's where I disagree with Zelaza: it doesn't need to be high-speed--but it does need to be 220v.

From Boston, I can get to the cross-country skiing at Jackson NH, but I can't get there and back without charging. This is a little village with no big hotels and very limited parking at the XC ski center -- so they're unlikely to reserve a spot or three for EV charging only. Until I know for certain how I can charge in Jackson, I can't take my Model S there.

This is just an infrastructure problem, though. If there were no gas stations in New Hampshire, I couldn't drive my BMW there, either.

brianman | 06. November 2011


Nobody on the planet says "how many round-trip miles do you get per gallon?"

Ramon123 | 06. November 2011

The 55 speed limit was adopted during the Carter years and had nothing to do with traffic fatalities - it was an attempt to fight
the oil crisis by increasing mileage. Failed at that and also failed to reduce highway fatalities (they actually increased as I recall-
one reason they were "officially" revoked) was widely ignored by the driving public.

Ramon123 | 06. November 2011

Knock off the crap about Zelaza. Believe it or not, you don't have to be an oil industry employee to see the problems that have plagued
electric cars for the past century. It's the battery, stupid, as they say. The cost, the lack of capacity, the excessive weight, the long recharge times, the short lifespan. Now, many of those deficiencies have been removed with the advent of the much improved li ion cells.
Recharging the Model S 300 pack in 45 minutes (assuming this to be true) pretty much eliminates the recharge problem. And weights are not all that inhibiting, at around 1200 pounds for the largest pack.
Lifespan needs to be improved and recent battery developments from Toyota and others seem to promise complete elimination of that concern. So right now the big bugaboo is cost. Looking at the Tesla pricing of the battery packs options leads me to conclude that the cost of the battery pack is going to be roughly $10,000 for every 75 miles of driving range. I believe that only in the price realm of the Tesla Model S are electric cars roughly competitive at this point, which is a big improvement and the first time this has ever happened. But at this price point, electrics will not be sold in sufficient numbers to have any effect on anything. That must wait for lower battery prices. Two developers so far have promised battery prices between 10% and 20% of their current price. That would do it. At that point, electrics are not only cheaper to run, but will be cheaper to buy as well, marking the end of the gas powered era. Until that happens electrics will remain niche vehicles, assuming gasoline prices don't skyrocket into the stratosphere. I've observed that EV enthusiasts tend to be ridiculously over optimistic and are getting ahead of the technology. It all comes down to the price of batteries. It's no more complicated than that.

Mycroft | 06. November 2011

Battery tech has made amazing strides in just the past 5 years. Do you think it's going to frickin stand still in the next 5 years???

It's a good thing you guys aren't in charge of where R&D funds are funneled or we'd still be lugging around 5 pound cell phones the size of a fricking brick!

Brant | 06. November 2011

I am going to agree with brianman about Zelaza; he is the official Tesla blog troll. A brief review of his posts will reveal a common premise that EV's, even the Model S, are not ready for modern consumers. Regardless of the topic; economic, utility, practicality, range, or other, he is consistently the naysayer posting verbose arguments backed up by handpicked and often misrepresentative facts and circular logic that conform to his agenda.

With regards to towing hardware on the frame; also agree. I think not having a spare tire in the car is a poor idea as the obvious outcome is the need for a tow with every flat. Not good advertising for a young car company in my opinion (every Model S with a flat tire gets paraded around town on the back of a tow truck). If I am not mistaken, the low profile high performance tires are more prone to flats than conventional sized all season tires.

My5bAby | 06. November 2011


I honestly appreciate the critique of my statement. Furthermore, I admit an error for not including developments in the "quality" of vehicles. However, I respectfully suggest you consider and admit the fact that, regardless of the "quality" of a vehicle, the faster you are going, the more you will be injured. It is a matter of simple physics. So the most correct and complete statement would include both quality improvements and slower speed of impact.


While it may appear that we are treating Zelaza harshly, most of us have NEVER seen a positive statement regarding EVs and/or Tesla from him. Reading the posts on the forum you will find many of us disagree about every conceivable aspect of the car company and technology. However, the underlying message is why "my" suggestion for the Model S is superior, unlike Zelaza's comments where the underlying message appears to be universally, "you should not buy this car or support this technology.".
Mr. I invite you scan through the various blogs yourself. If you come to a different conclusion regarding Zelaza, please let me know, reference the post/s and I will personally give Zelaza a sincere apology and will defend his motives in the future if I perceive someone else is misunderstanding his intentions.
I however would wager that you will come to the same conclusion that we have, and find yourself asking, "why is Zelaxa spending so much time posting in this forum?".
Certainly another reasonable purpose might simply be to get attention. However, even if that is true, the reality is we are trying to get this company / technology off the ground and this is a very vulnerable stage.

The only reason I have not ignored Zelaza is because he echoes and represents what we are up against. While some may say this therefore makes him helpful, I would liken it to having a member of the opposing football team secretly on our team, in our huddles, locker room and practices, always saying, we can't beat their defense, we can't stop their offense, our team is not ready, our coach & quarterback are making the wrong decisions, this is a bad sport, we should be spending more time at home, we are neglecting our family and friends by being here etc.

A player who did that would have his motives questioned, then be asked to leave, and thus we have done the same.

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My5bAby | 06. November 2011


I STRONGLY DISAGREE WITH YOU. If they were in charge of R&D they would have said, what's the point of a cordless phone if you have to keep putting it back in the cradle to keep it charged. If you forget, your phone is dead, has that ever happened with a normal phone? Plus what happens if you forget where you put it? Sure you can take it out by the pool but if it gets wet it's ruined! Until a cordless phone can have a week of talk time, unlimited range from the base, be water & meteor proof, the technology just is not ready. It should not even be pursued or offered to anyone.

Hey, did I just succinctly describe the obvious about cordless phones, Range Anxiety !

We need to start small with something like a, I'll call it a Golf Cart. We can slowly add range, size and features and then all the sudden they will be adopted by the masses and replace ICE vehicles :-)

Oh, that's right, we tried that :-(. Now the term Golf Cart is derogatory and turns people away.

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Timo | 07. November 2011

@Ramon123 "Recharging the Model S 300 pack in 45 minutes (assuming this to be true) pretty much eliminates the recharge problem.

Why wouldn't it be true? There are Li-ion batteries out there that can be charged in less than five minutes. All it takes is power. Lots of it for battery sizes of 90kWh. For 45 minutes roughly 90kWh/0.75h = 120kW. Probably 500V * 240A or something close to that. Not too much to handle.

Volker.Berlin | 07. November 2011

Looking at the Tesla pricing of the battery packs options leads me to conclude that the cost of the battery pack is going to be roughly $10,000 for every 75 miles of driving range. (Ramon123)

I would not make any conclusions regarding the actual price of battery tech based on Tesla's option pricing policy. It is far too easy to come up with arguments why Tesla should overcharge (maximize gross margin on more expensive configurations) or undercharge (push high range battery into the market to help market share and brand reputation). IMO, the actual battery cost is mixed into Tesla's magic sauce and you will not learn anything by looking at Tesla's consumer prices.

brianman | 07. November 2011

"I am going to agree with brianman about Zelaza"
Woah. That's My5bAby's pitch. I just think his "you must think in round-trip, so let's halve the numbers" is specifically asinine.

brianman | 07. November 2011

"regardless of the "quality" of a vehicle, the faster you are going, the more you will be injured. It is a matter of simple physics."

Incorrect. It's an issue of -a- do you have an impact (wreck), -b- what's the deceleration like, and -c- mitigating factors such as airbags.

Volker.Berlin | 07. November 2011

brianman, I am sure My5bAby implied "all else being equal". Given the same vehicle with the same "quality", crumple zone, airbags etc., the damage increases with the speed at which an accident occurs.

My own comment on the issue: There is a lot of psychology going on, e.g., when airbags were first introduced some studies observed that drivers tended to more risky driving style b/c they felt safer, leading some to the conclusion that the positive physical effect of airbags is canceled out by the negative psychological effect on driving behavior. I think there is something to it (I wouldn't feel easy going fast without my seatbelt fastened -- you may argue whether that makes a difference or not when I hit a wall a 80 mph, but in any case, it *feels* safer) although I would hesitate to quantify the effects.

brianman | 07. November 2011

"all else being equal"
The zealot wisdom was "surely it would be safer if..." and the statistics proved otherwise. From that point, it went to "I didn't mean to imply" but then "let me make another assertion that surely you will agree with".

If you want to start a discussion on that topic, go nuts. But let's not mix up the topics.

Robert.Boston | 07. November 2011

re Zelaza: just because he appears to be an EV foe doesn't mean that everything he says is wrong. Moreover, it's good exercise to address his arguments, inasmuch as what he's saying here will be (and is now being) said in many other forums. We need good answers to valid-sounding points of EV critics.

re batteries: when I last met with the CFO of the U.S. Department of Energy about prioritizing DOE R&D dollars, I singled out energy storage as the most critical element, and one that needs more funding. Storage complements all the other techs that DOE is funding -- even if breakthroughs in solar or ocean tech are made, without a way of storing that intermittent power, we'll still need an overbuilt transmission system with lots of fossil-fired power plants.

petero | 07. November 2011

Lots of interesting feedback. Thank you. However… we are straying, a bit.

I would also like to hear from Roadster owners who can verify their real world observations about power, charging, miles per charge, etc. I realize that no Roadster owner will drive until the battery is depleted, so lets take a normal daily drive of say 100 miles. Virtually every Tesla owner and future owner will drive and recharge at night or at work , probably both.

How was your Roadster’s (power, mileage) when new…how is your Roadster after 1,2,3 years. I have only driven a Roadster for a brief, exhilarating,, few minutes, do you only recharge to 80% and how does this effect everything?

Specifically, if I were to purchase the 160 mile battery I would not expect to realize the full 160 miles driving range due to spirited speed, accessory usage, etc. Most traffic goes 75-80 mph on the freeway in Southern California …or it is bumper to bumper. I would anticipate the 160 would be a “real world” 130. Now if I only charge my battery 80% is the 160- 130- really 104?

So you drove your Roadster 100 miles. You charge the battery to 80%. What does your gauge indicate you have left in range?

Appreciate your feedback.

Mycroft | 07. November 2011

"Now if I only charge my battery 80% is the 160- 130- really 104?"

Yep. Hence my statement that if you routinely drive more than 100 miles on a charge, you should upgrade to at least the 230 mile battery pack.

petero | 07. November 2011


Thank you. You just cost me $10K but saved me from making a more expensive mistake.