For Elon Musk the 100 kWh battery is enough for now

Tesla Model S battery

Elon Musk, Tesla Motors CEO used Twitter to say that he’s pleased with the current battery capacity.


Here is what he wrote:


This statement implies that further battery improvements will probably focus on faster charging, more power, better lifespan, increased efficiency and lower cost.

GM recently proved with the Chevrolet Bolt EV that it’s possible to have an electric car with decent range and still being very efficient. This might have influenced Musk to start pursuing better efficiency.

In terms of aerodynamics Tesla’s electric cars are already very good, but they could be better. Aero wheels and mirrorless versions should at least be optional in the near future.

Regarding weight reduction, it will be possible with the new more energy dense cells that will be produced in the Gigafactory. Not only the battery will be lighter but also smaller for the same battery capacity. The battery volume reduction will also enable the use of lighter, smaller and less complex TMS (Thermal Management System) and BMS (Battery Management System).

Even the powertrain and the electrical system as a whole can always be more efficient, especially the well known “vampire drain” in Tesla electric cars can be reduced. The Bolt EV efficiency is a big surprise since it’s not a light nor aerodynamic car, GM and LG Chem did a great job by making the powertrain so efficient.


Achieving an official 400 miles (644 km) EPA range in a Tesla Model S 100D can be possible with future efficiency improvements. Better aerodynamics and lower weight not only contribute to better efficiency but also better performance.


Not to forget that the standard 10 kW charger already takes more than 10 hours to fully charge the 100 kWh battery since it’s not 100 % efficient. A bigger battery capacity would inevitability increase the charging time in most homes. This is another reason why further range improvements should come from increased efficiency, not brute battery capacity.

I hope that Elon Musk is really working to improve the efficiency of Tesla electric cars, but his statement can also be a way to incentive potential buyers to get a Tesla now instead of waiting for further battery capacity increases.


What do you think?

Pedro Lima

My interest in electric transportation is mostly political. I’m tired of coups and wars for oil. My expectation is that the adoption of electric transportation will be a factor for peace and democracy all over the world.

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5 years ago

My theory is that Tesla really pushed the limit of the 18650 cells with the P100D and that it might be difficult to safely pull such huge numbers out of a 100 kWh pack consisting of 21-70’s because there will be considerably fewer cells. Maybe a 110 kWh pack consisting of 21-70’s will give about the same power potential or maybe even a little less, then it wouldn’t make as much sense to keep pushing with today’s cell technology. So I think they will keep the 18650s for the P100D for now and release the normal 100-versions with 21-70 cells when the GF has got the production going. Also the cars are getting really heavy, it makes sense to await further improvements in cell chemistry instead of just putting more batteries in the cars at this point. Their drive units are taking a serious beating as well with ever increasing power and weight.

I also hope that they will focus more on efficiency, refining charge/discharge rate of the 21-70s in regards to lifespan and also profitability.

5 years ago

I would assume that the 2170 cells are not a direct drop in replacement for the S and X due to an increase in size…

If Tesla also wants to increase efficiency they might want to drop the performance aspect some so they can have smaller tires and wheels unless they need ones that gargantiun simply due to the S and Xs weight…

Rotating weight has a huge effect on effiency and larger tires and wheels can take a couple MPG off the edfiency of gas cars which I unfortunately know from experience…

Tommy Duhn
5 years ago

I think it’s fine to stop at 100KWh – FOR NOW. Defintely not forever. I doubt it will even be possible to stop for 10 years, as I think a lot of “low-end” EVs will start approaching that 100KWh capacity in 10 years time. By then we’ll also see 350KW fast chargers for travel, and I assume faster charging at home, too (30+ KW would be nice).

I hope that by 2030, all new EVs, whether they cost $10,000 or $50,000 will have at least a 100KWh battery. If batteries keep increasing density by 2x every 4 years as they do now, then by 2030, the current 100KWh battery should be at least 8x smaller.

Tommy Duhn
5 years ago

One thing I forgot to mention, I really doubt Tesla will use this opportunity to “lower prices”. Maybe for some upgrades it will – like if you want to go fro a 60KWh battery to a 100KWh battery, it should cost you much less in the future. But not for the “default base”. Instead of making Tesla Model S 60 $50,000 from $66,000, I think Tesla will just add other stuff, like more cameras, more sensors, perhaps LIDAR, or other stuff like that.

I do wish they made a sub $15,000 EV, though, because I just don’t think the “self-driving” revolution with 80% of the people wanting to take a self-driving cab to work every day, rather than taking their own car, will arrive as soon as Musk thinks it will. Not even in the U.S., let alone in a country like India.

So if it already takes 15+ years for that revolution to arrive, then it doesn’t make any sense for Tesla to hold out on an even cheaper model. I hope Musk will realize this, too, before some other car maker like Renault completely dominates the sub $15,000 segment. As Pushev showed recently, too, the top 10 cars in Europe are almost all under $15,000.

Ralf K
5 years ago
Reply to  Pedro Lima

Taking Fiat 500e sales in CA und Oregon as a reference for success is like taking e-Golf sales in Norway as a reference. I consider this completely pointless as other states and countries have different conditions. California even *enforces* EV sales at a certain percentage of ICE cars. So car makers need to bring BEVs to CA – or buy ZEV certificates from e.g. Tesla from their share.

When you hope, Tesla will make smaller cars for people with lower income, Elon Musk has an alternate imagination/vision: finance or lease the Model III with automated driving capabilites and let it earn money (being a carshared robotaxi for others) when you do not need it. This way, owner cost will drop to the costs of a smaller car without Tesla having to make a smaller model. It is still a big and heavy car, but with a better utilization.

Ralf K
5 years ago

Tesla still has quite some efficiency potential in its electric motors. They still use asynchronous motors (that need an external electric current to create the magnetic field via induction), which are less efficient than synchronous motors. But this way, Tesla does not need rare earth metals such as Neodym and Dysprosium for the motor, which would increase the dependance on Chinese imports and variable price politics. Or would necessitate to start exploration to find these metals in US mines.

Essentially the rest of the industry (including Bolt EV) uses permanent magnet synchronous motor. There the magnets are magnetic by their material design (Neodym-Iron-Bor magnets, Dysprosium added for better thermal range), they do not an need external current to become magnetic. But to make strong magnets, so far you need the rare earth metals named above are necessary.

In addition Tesla could right-size peak engine power to a more reasonable level, emphasizing real-world efficiency instead of acceleration times. And from there: right-size cooling, inverter, power electronics, brakes.

5 years ago
Reply to  Ralf K

The Renault ZOE doesn’t use rare earth metals either. ZOE is designed for Mass Production.

5 years ago

If Tesla shall be able to improve efficency they have to focus on the rolling resistance. The aerodynamic is already very good, but a car that has a top speed of 250km/h can not use tires that is optimized for low rolling resistance. Most european countries have a maximum speed limit of 130 km/h. So in many ways it is insane to produce a car that is able to drive almost twice as fast. To be able to use more efficient tires the most logical choise would be to limit the top speed to about 160Km/h.

5 years ago

What some people are losing sight on is that the 21-70 batteries are going into the model 3 first.

There will be quite a large saving of size and good bit of weight with these batteries. Model S and X will transition to 21-70 batteries after then model 3 production is under control.

It would not make sense it use new 21-70s for model S when they need to get model 3 out the door. I thought that maybe they would make a bigger model S battery using 21-70s but they did not, which means that model 3 gets the 21-70s.

I wonder what will happen to 18650s there is quite alot of production capacity for them, will they use them in powerwalls after model s is on 21-70s.

I dont think tesla will change from asynchronous motors , they have alot of R and D in them, and remember they are making their own inverters that are more efficient that off the shelf , so in the long term is doesnt matter, because in manufacturing it is simpler and the supply is not an issue.

I mean to make one of their motors you just need raw materials, no rare earths thats HUGE going forward, easy to ramp up for model 3 and other tesla cars/trucks , half a million cars without having to use rare earths is a big saving in headaches.

The next time the battery is updated for size it will be probably to charge quicker, the 100d (not P) will easily do 350miles , thats enough if you have superchargers, but knowing tesla they will want supercharging times down, imagine halving the supercharger time, i think thats what tesla will be going for.

Teslas new p100d battery is really simple, they now do not run coolant past the batteries but have heat sink fins that connect the batteries to the coolant at the bottom, that is a huge manufacturing advantage going forward, tesla is keeping it really simple and thats why there batteries are the cheapest.