Battery weight

Battery weight

Just curious. A number of friends have played devils advocate concerning the added weight the battery must have. What's the weight of the engine for a 5 series or an A6?

Mycroft | 24. Oktober 2011

The batteries plus motor are heavier than a conventional ICE vehicle. Not sure about the weight of a fill gas tank.

Mycroft | 24. Oktober 2011

Meant to say ICE vehicle engine.

mwu | 24. Oktober 2011

Also to note is that the A6 has two engine options -- 4 cylinder 2.0T or 6 cylinder 3.0T. The 3.0 gives similar 0-60 times as the Model S, so that's what you'd likely want to compare against.

Denis Vincent | 24. Oktober 2011

The weight of an Audi A6 with a 300H.P. engine is 4123 lbs. It does 0-62 mph in 5.5 sec. Weight of the Tesla S is 3825 lbs. I drive an Audi Allroad, fabulous Automobile, can't wait to get my Tesla!

Denis Vincent | 24. Oktober 2011

The weight of a BMW M5 is 4288 lbs. with a 560H.P. engine. It does 0-62 mph in 4.4 sec. Apparently, The Tesla Model S Sport will do 0-60 mph in less than 4.5 sec.

sarge7359 | 24. Oktober 2011

Comparing battery weight to engine weight reminds me of the other comparison threads; where do you start/stop adding components to the "engine" vs "fuel"? Where does the exhaust system factor count? Alternator? ICE battery?

The battery might be more comparable to the fuel tank (full, please) plus transmission? The electric "motor" is actually in the wheels and the weight is probably significant to the overall.

I'm also guessing Denis V might go for the sport option for the faster 0-100kmh?

ThomasN | 24. Oktober 2011

I guess a more accurate comparison would be the model s battery and motor weight compared to an ice motor, full fuel tank, tranny, 3rd member, differential and exhaust.

Timo | 24. Oktober 2011

Weight difference is not big between entire ICE drivetrain and Tesla drivetrain. Problem with comparing numbers is that if you try to find ICE weights you find engine block weight, not the entire drivetrain.

Volker.Berlin | 25. Oktober 2011

Weight of the Tesla S is 3825 lbs. (Denis Vincent)

Denis, where did you find this number? I am still looking for a source stating anything more precise than "around 4000 lbs".

To the topic: The comparison really does not make any sense (and that's not meant in an offending way). The real topic here is range, and you cannot compare the range of an ICE/Hybrid with the range of a BEV for known reasons: It takes mere minutes to refill the gas tank, and it takes hours to recharge the battery.

If we leave range aside, simply take the 300 mile model, cut the battery in half (which is slightly different from taking the 160 mile model due to different chemistry) and the "battery weight problem" goes away. But so does half of your range.

Tesla has made tremendous efforts to bring down the weight of the Model S's chassis. The purpose of that exercise was not to come in at some weight number comparable to that of an ICE of the same size. The purpose was to increase range because less total weight means that less energy is needed for propulsion (direct effect on acceleration, smaller effect by way of rolling resistance on keeping speed constant). And less chassis weight means opportunity to add in more batteries.

I am not sure if I can get my point across. The comparison is futile in a fundamental way. The Model S is all about shifting as large a fraction of the total weight as possible into the batteries, for any given total weight. And it's about reducing the total weight as much as possible to reduce masses and improve acceleration and rolling resistance. You can easily achieve almost any given weight be increasing or decreasing the battery. It's all about an intelligent compromise.

Nicu | 25. Oktober 2011

Guys, you fret so much about some things that you become to disinform each other. Second video in the Model S unveiling blog entry, 0:20 (the most recent info from the horse's mouth, no doubts about pronunciation or any other BS)

"Model S is a little over 4000 lb"

Timo | 25. Oktober 2011

There is a small point in the exercise. Is usable range EV heavier or lighter than ICE? We are at the edge where there is no point having ICE in the car, because that just plain increases weight in car that would be more useful to increase batteries instead. The limiting factor is no longer the weight of the batteries but price of the batteries.

300 miles is not quite enough to crush ICE. 500-600 miles is a range where you no longer need on-road charging at all for 99% of driving(ten hours of driving at 60mph average speed. Anybody would require long break after that). After that ICE is just plain obsolete.

If you can recharge 80% of 300 mile battery in 45 minutes then 600 mile version would take 1 1/2 hours for same 80%. After ten hours of driving I would welcome such a break.

EdG | 25. Oktober 2011

And once that milestone (500-600 miles on a charge) is reached, I'll want more just to have more.. About as much as I'd like my cell phone to hold its charge and be continuously useful for more than a day. Then I'm free to travel without worry about where I'm going to get my next fill-up.

Robert.Boston | 25. Oktober 2011

I want those batteries that the Star Trek phasers have: little handheld devices that can generate continuous beam ray sufficient to melt large masses of rock. Oh yeah. Have you ever noticed we never see them tuck those puppies back into recharging stands?

I digress; as Volker and Timo correctly point out, weight is irrelevant. It's a proxy for several things that are directly measurable:

  • Acceleration
  • Range
  • Ride stability/comfort
  • Handling
  • Safety

So...just focus on the relevant endpoints, not the poor proxy.

Volker.Berlin | 25. Oktober 2011

So...just focus on the relevant endpoints, not the poor proxy. (Robert.Boston)

Thanks, Robert. That's exactly what I was up to.

mwu | 25. Oktober 2011

For my own preference, I think I'd rather stop after about 5 hours and have a good meal -- that's about how long I go before I'm hungry after a meal. Go inside and have a nice sit-down meal... By the time you're done, the car is charged (assuming a fast charger is available).

Timo | 25. Oktober 2011

@mwu So you still want a bit more than 300 miles, because that would be five hours drive without margin at 60mph average speed. Assuming you can get 300 miles with average speed of 60mph that is. I think Model S EPA-rated 300 mile is achieved with 50mph.

Or even more. 80% of the battery can be charged in 45 minutes using Tesla fast charger. Rest of the battery takes a lot longer. 300 / 0.8 is 375. That is a minimum before it could be enough for you.

Close, but not quite yet there. Next few years give that breakpoint, I'm sure about that, but not yet. I hope that when Tesla (or someone) makes a EV that is actually useful for me that breakpoint has been achieved and my country stupid tax laws have been revised (Finland has probably oldest car base in entire Europe because no-one except really rich or really car-enthusiasts can afford buying a new cars).

ThomasN | 25. Oktober 2011

Ask a simple question...
The whole point was to fill in the blanks to the following generic conversation

- ... Getting the model s with the 300 mi range

- won't the battery weigh alot?

- yeah it will. But the weight is ___lbs, while the weight of the engine, tranny and gas tank on your 5 series is___lbs. And, all that weight is on the bottom of the car.

I've had this conversation several times, but without the numbers.

No offense, but I'm quite sure the people I've had these types of conversations with aren't really interested in the political answer of why the question isn't relevant. They just want the numbers.

Numbers only please.thanks!

Volker.Berlin | 25. Oktober 2011

- yeah it will. But the weight is compensated for by an all-aluminum body that has been specifically designed to integrate the battery as a structural part. That way Tesla can put in a huge battery (300 miles, as compared to 50-100 miles for the Leaf, according to Nissan) and the whole car still weighs pretty much the same as your 5 series. Your 5 series may actually be heavier than the Model S if you have one of the larger engines. And, all that battery weight is on the bottom of the car.

Mycroft | 25. Oktober 2011

The curb weight of a Panamera is around 4,300 lbs and should include a full tank of gas. The maximum weight of the 300 mile Model S that we've heard about, (from my understanding), should be about the same.

@Volker.B: "And, all that battery weight is on the bottom of the car."

That's the best part!!! Creates a fantastic ride and rock stable suspension! Not to mention the safety issues.

Safety-wise, the Model S wins hands down. Would you want an engine in your lap in a 60mph head-on collision with a drunk driver? How 'bout that protection provided by the battery in a side collision?

Nicu | 25. Oktober 2011

From the Model S features page:

"Model S comes standard with everything you need to plug into the most common 240-volt outlet, standard 120-volt wall outlets and public stations. Using a high-amperage 240-volt outlet, Model S can be recharged at the rate of 62 miles range per hour. It can be recharged in 45 minutes using a DC rapid charging station."

There is no 80%, just that it can be charged in 45 minutes. I do not understand why people make up things!

Volker.Berlin | 25. Oktober 2011

Nicu, it's not made up. The last 20% are much slower to charge, at least that's what I have heard repeatedly, too. Here is one source, the information has been up on Tesla's website until the recent website face lift:

It is my understanding that the PEM won't even let you use the last 10% or 20% -- it does not allow to fully charge, neither to fully discharge. That's why there is the "range mode" which needs to be engaged already while charging: It allows for charging closer to max capacity and allows for further discharging. At least for the Roadster, it is not recommended to use "range mode" on a regular basis because it will wear out the batteries faster. There is no user guide for the Model S available yet, but until we have something more explicit, it is probably a good approach to assume that battery charge/discharge should have characteristics similar to the Roadster.

Larry Chanin | 25. Oktober 2011

Hi Thomas,

This Wikipedia article puts the weight at 1,200 pounds for the large battery pack.

I don't know how accurate it is since it inaccurately states the weight of the car is 3,825 pounds.


Nicu | 25. Oktober 2011

The Roadster had laptop batteries inside. Even as they are 18650 cells too in the Model S, they have been developed in collaboration with Panasonic for this car. They should have better characteristics like abuse tolerance, better life cycle etc. If Model S only gets 300 miles on a forced full charge that is not recommended, then it is half false advertising to say it has that range. One should state the standard range and explain that in rare cases you could get futher. I'm not saying this for myself, but there are a lot of wolves out there waiting for the slightest opening to attack.

EdG | 25. Oktober 2011

During the Oct 1/2 weekend, Elon said, if I remember correctly, the Model S has been tested and will be able to achieve 320 miles (325?).

80% of 320 is 256... So the daily recommended maximum range might be 255. But that would be only for people who are using that distance every day, or many days.

The majority of us who opt for the 300 pack will want it once in a while, and will generally know if the extremes of the range are necessary. On those days we would charge it to the max...

David70 | 25. Oktober 2011

Right EdG. At home I'll only slow charge at 120V and problem never drive more than 70 miles in one day, and not likely do that far for two days in a row. Once enough rapid charge stations are established, for a road trip I'd range charge before leaving, do standard charging along the way and range charge while charging over night at a motel with a 9+kW charging station. There's no reason one couldn't do 500 miles a day that way. Not as much as the 750 miles I sometimes do, but it wouldn't add more than a day to a 1500 mile trip.

Denis Vincent | 25. Oktober 2011

Thanks Larry, my source for the weight also came from Wikipedia. However when attending the Event, I at Elon's presentation(I'm the guy with a big smile on my face) he did indeed say that it weighed in at a little over 4000lbs. This may have applied to the vehicle he arrived in, which had the retractable glass sun roof, the rear seats, the 21" tires and more then likely the 300 mile range battery which would easily add up to 175lbs. In any case, who gives a f....!

Volker.Berlin | 25. Oktober 2011

It is funny how in this case people believe Wikipedia. As if Wikipedia would know before Tesla knows. Wikipedia, useful as it is, is always second-hand information. Without looking at the sources of the information, the information is worthless. Particularly so for some tech product that is still in development, with only partly published specification.

I frequently use Wikipedia, but for the Model S, the references section is the only information I use from their page.

brianman | 25. Oktober 2011


Since you like the references...

"Acceleration of the 3,825 pounds (1,735 kg) vehicle is anticipated to be 0–60 mph (97 km/h) in 5.6 seconds aided by a drag coefficient of 0.28.[26]"

"26. ^ Ramsey, Jonathon (2009-03-26). "Tesla Model S: $50,000 EV sedan seats seven, 300-mile range, 0-60 in 5.5s". autobloggreen. Retrieved 2009-04-12."

The title in that Reference points to...

.. an article from Mar 26th 2009, which notes ...

"Curb Weight 3825 lbs"

So basically in May 2009, those were the specs as Mr. Ramsey knew them. It seems like they've drifted upwards a little in a couple years.

As many have said though, I don't think it's worth getting one's feathers ruffled about it.

Volker.Berlin | 26. Oktober 2011

brianman, thank you! :-) I don't know about others, but to me it makes a great difference to say "when the Model S was first announced two and a half years ago, the anticipated weight was stated as 3825 lbs" vs. saying "the Model S weighs 3825 lbs" when there are already Beta models driving around with an unknown (to the public) actual weight.

brianman | 26. Oktober 2011

Glad to help. :)

perbakken | 26. Oktober 2011
Volker.Berlin | 26. Oktober 2011

Well, 2015-2020 is still a broad range, and there has been no shortage of future battery tech announcements in the last few years. Let's just watch and see what happens...

Timo | 26. Oktober 2011

Weight has gone up, but Cd has gone down. A lot.

I think we need to wait for numbers appear here in website before we can get any clear answers to weight, Cd etc.

As much as I trust Elon, he is not the engineer behind stuff, he is enthusiastic leader, visionaire and investor with some clue about stuff that people in Tesla tell him. I would trust JB Straubel or Peter Rawlinson more than I trust Elon for accurate numbers.

Volker.Berlin | 26. Oktober 2011

There is no 80%, just that it can be charged in 45 minutes.

If Model S only gets 300 miles on a forced full charge that is not recommended, then it is half false advertising to say it has that range. (Nicu)

In a recent interview, Musk claims Tesla's technology can charge at "100 miles every 20 minutes". Note that he does not say 300 mph although that would be mathematically equivalent. One possible reason might be that he wants to avoid the impression that the 300 mile battery can be charged to the max in 60 minutes. 100 mi/20 min equals 225 mi/45 min, which is pretty close to 80% of 300 mi (240 mi). The last 20% may take considerably longer than another 15 minutes.

Note that I am really just guessing here, trying to fit some puzzle pieces together, but I am still waiting for some official/public confirmation of my assumptions.

Volker.Berlin | 27. Oktober 2011

Regarding the 80%/45 min fast charge issue, here is another puzzle piece:

Tesla claims that the Supercharger would take any Model S from a 10 percent to a 90 percent charge in 45 minutes, but Mr. Straubel said in an e-mail that the company would prefer to focus on "recovering more than a 50 percent state of charge in 30 minutes of charging, or 150 miles of driving range in 30 minutes with the 300-mile-range vehicle."

Straubel's 150 mi per 30 min conspicuously matches the 100 mi per 20 min mentioned by Musk in the BI interview (link in previous post). And again, Straubel carefully avoids saying anything that would sound like 300 mi per 60 min.

Mycroft | 27. Oktober 2011

And also avoids saying why he focuses on the 50% in 30 minutes deal. Of course it's probably to limit damage to the batteries.

Robert.Boston | 27. Oktober 2011

Another interesting, subtle difference between Musk's and Straubel's comments: Musk describes the charge speed in miles-per-charging-hour, whereas Straubel talks about "percent state of charge." Does this imply that quick-charging a 160-mile battery for 30 minutes adds only 80 miles?

Mycroft | 27. Oktober 2011

That's the implication. I'm sure the manual will go into a lot more detail. I'm also sure the computer will be programmed to charge while protecting the battery as much as possible and that you would need to put it in range mode to charge up to the full 100%. Yet another reason to buy more battery than you need.

If your commute is 80 miles or less with the occasional 20 mile side-trip, then the 160 mile range would be perfect. But if you would fairly regularly drive 120+ miles, then you'd likely want to spend the $10k on the larger battery.

Zelaza | 27. Oktober 2011

Do some numbers people, do some numbers!
Even if the type of batteries described were available, you run into the inconvenient issue of a power source capable of charging the battery, Assuming 3 miles/kWh, 150 mile range requires 50 kWh of energy. To collect this in 30 minutes requires a charge rate of 100 kW. Where outside of an industrial location are you going to find that size of a power terminal? I think that the 3 or 4 neighbors that share your 50kW secondary transformer from the power utility will not be too pleased if you're trying to suck up 100 kW for half an hour.

Mycroft | 27. Oktober 2011

Zelaza, we're not talking about home charging. :-p

Volker.Berlin | 27. Oktober 2011

My internet access used to be 56 *kilo* bits per second (and that was the faster of the available modems). What do I have at may home today? I do not even know, actually, b/c it's good enough that I don't care. Looked it up, it's 16 *mega* bits per second. Agreed, there is a qualitative difference between kilo bits and kilo watts, but the infrastructure will be growing with the job.

Zelaza | 27. Oktober 2011

You're right. Moments after pressing the SEND button I realized that this charging was, probably, not intended for home use. My bad :-(

There really is more than a qualitative difference between bits and watts. While we encourage the consumption (utilization) of bits, one of the premier reasons for converting to EVs is to reduce world energy consumption. Increasing the electrical energy available, and encouraging its consumption, is probably not the way to go.

Volker.Berlin | 27. Oktober 2011

@Zelaza, I beg to differ. An efficient and capable grid has nothing to do with increasing the electrical energy available. There is enough electrical energy available, anyway. An extension of the grid is desperately needed (just as well in the USA as in Europe, I guess) to use the available electrical energy efficiently, and make it available where it is needed. Particularly the desirable switch to renewable energy sources requires a capable grid as a prerequisite. Well, there are other threads already in this forum that discuss the different ways of producing electricity, and their very different characteristics. Suffice to say, improving on the grid can only do good and does not mean increased energy consumption. Quite to the contrary, actually.

Brian H | 27. Oktober 2011

About miles vs. %, I suspect Straubel is being more technical, since miles/kwh depends on driving conditions and habits. 150 mi. at 100 mph. on the Autobahn is different from 150 mi. at 70 mph. on a US freeway.
As much as I trust Elon, he is not the engineer behind stuff, he is enthusiastic leader, visionaire and investor with some clue about stuff that people in Tesla tell him. I would trust JB Straubel or Peter Rawlinson more than I trust Elon for accurate numbers.
I wouldn't bet 5¢ on that, if I were you. Elon is stuck in up to his eyeballs on the tech, and probably makes all the go/no go decisions on such things--not to mention pushing the envelope everywhere. He IS an engineer, and a brilliant one.

Brian H | 27. Oktober 2011

Just to continue the above, his mother mentioned that from a young age he had eidetic memory, and could recall exactly whatever he'd read. Whenever anyone wanted to know anything, his sisters used to say, "Ask Genius-Boy." If he'd read it, he knew it.

When asked how he learned "rocket science" to start SpaceX, he said, "I read a lot." It took him a couple of months to get to the boundaries of what's known.

Timo | 28. Oktober 2011

Still, he is not the engineer behind the stuff. Elon just can't know everything, just what those engineers tell him, so anything coming from Elon is second hand knowledge unless it is some decided number which is a goal he had set that can't fail.

Nicu | 28. Oktober 2011

You're wrong Timo. As an example, he figured why one of the most important rocket launch failed at SpaceX. Without that, the company would have probably failed. Only someone who knows very close to everything about the rocket could do that.

Zelaza | 28. Oktober 2011

" When asked how he learned "rocket science" to start SpaceX, he said, "I read a lot." It took him a couple of months to get to the boundaries of what's known. "

The boundary of anything substantial is only skin deep. You can't possibly be serious with this comment. Perhaps that explains why Musk left graduate school at Stanford after only a couple of days; that's all the time it took for him to learn everything they could teach.

" Without that, the company would have probably failed. Only someone who knows very close to everything about the rocket could do that. "

Oh! Pulleeezzze.

Nicu | 28. Oktober 2011

You clearly did not have any deep problem to solve ever, nor any Eureka! moment.

Brant | 28. Oktober 2011

I am beginning to think he has a very deep problem...but i don't know that there is a solution.