Model S battery can not be replaced with a different size battery

[mknox]

Okay, not to be too much of a nit-picker, but do they mean physical size or battery capacity. They are two different things. Obviously, the pack size is designed to fit into the car and it should be obvious that you can't replace with a different size after the fact. (I can't put D-cells into my flashlight designed for AA-cells).

 

[Longhorn92]

But we don't actually know what differences there are between the 85kWh and the 60kWh. Are all the wiring harnesses the same? Do the battery packs have the same weight? Same CG? Are the suspension setups the same? Do they have different programming? Different firmware?

I am listed the exact text from an e-mail from Walter Franck below. Again, this was from March 2012:

Hi Brett, thank you for contacting Tesla Motors.

The power electronics, inverter and motor will be the same between the 3 batteries. Model S comes standard with a 10 kW charger and can be upgraded to the 20 kW twin charger after delivery. There will be firmware differences between the different battery packs, but hardware will remain the same. Model S Performance will have different hardware outside of the battery to allow the increase in acceleration, this cannot be upgraded after delivery.

The one important difference to keep in mind is Supercharging. This requires special hardware that bypasses the on-board chargers as well as more robust wiring capable of handling 90 kW of power. When built, the 40 kWh will not have the hardware required for supercharging and cannot be upgraded afterwards with that hardware. So while possible to upgrade from a 40 kWh battery to and 85 kWh for extra range and an improved 0-60mph, supercharging will not be possible. A 60 kWh vehicle purchased with the supercharging option can be upgraded to an 85 kWh and have access to the supercharge network.

Note that it will be some time before we have the flexibility as a company to upgrade batteries, our recommendation is for our customers to purchase the battery that best meets their current and future needs.

Let me know if there is anything else I can clarify.

Walter Franck | Ownership Experience Advocate

 

[ModelS8794]

I respectfully disagree.

I think this is terrible. Like saying "if you aren't rich now don't bother buying our cars with any longevity in mind." As a shareholder, this worries me immensely.

...I bought a 60 kWh because I could not justify the cost of the 85 kWh battery pack right now. This car is 2x as much as any other I have previously purchased. I can only justify that by saying that I will keep it twice as long as any I have previously owned as well as because it is more environmentally friendly, and would expect that as technology evolves then battery replacements should evolve with it. ...

This makes absolutely no sense to me.

Cheers.

I don't know if the analogy is perfect, but I have never questioned why my 1999 Accord couldn't have its 2.3L 4 cylinder engine upgraded to a 3.5L v-6 engine once Honda started producing them for later model Accords. I bought what I could afford at the time, and had no expectation that technology progress would allow me to retrofit the engine and have the car evolve in that fashion.

I think Tesla's ability to update features through software improvements that on other cars would necessitate hardware replacement is the bees knees. But I don't see how anyone might expect hardware improvements in the same fashion. I struggle to think of another product I own where I can improve the hardware that way. I guess I can add more memory to my laptop, but only to the maximum capacity engineered into the laptop at the time, right?

 

[David Johansson]

Your car won't be "outdated" because new batteries come along. It's a great car today, it'll be a great car then too. But of course you won't recoup what you paid for your car. That's the way it is with cars.

I think Tesla is doing the right thing. If they can't promise it can be upgraded, they shouldn't. Yes it would be great if they could, but better to be honest.

 

[mnx]

I find this a little disappointing but I have a feeling that if Tesla decides not to offer upgrades down the road then the aftermarket will.

Since I've ordered an 85kWh pack I sure hope the replacement battery I get down the road uses different cells and is hopefully lighter.

 

[markb1]

I think they're implementing this policy because they want people to buy the biggest battery they can afford right now, since that will help their bottom line. If there's a technical reason, they would (hopefully) say that. But I can't see what that technical reason could possibly be.

 

[Iz]

Okay, not to be too much of a nit-picker, but do they mean physical size or battery capacity?

I would tend to think it is capacity. Newer batteries would have to fit into the physical pack. Years from now I doubt those having a 60kWh pack will want to upgrade to 85kWh when 120s are available and perhaps at a lower price point. This of course assumes moderate advancements in chemistries.

 

[Bucket22]

I note that Tesla is not quite as definitive on their current Model S facts page (Model S Facts | Tesla Motors). They even assert that an upgrade is "technically possible":

"While technically possible to upgrade to a larger battery, we recommend configuring your Model S with the battery that meets both your present and future needs."

 

[stopcrazypp]

I note that Tesla is not quite as definitive on their current Model S facts page (Model S Facts | Tesla Motors). They even assert that an upgrade is "technically possible":

"While technically possible to upgrade to a larger battery, we recommend configuring your Model S with the battery that meets both your present and future needs."

I remember that line too. The quote on the board is more blunt and says it's not possible. So don't count on an upgrade being available. Also things may have changed now that the 60kWh pack is actually finalized (so they are better able to assess the viability of swappable packs).

 

[ElSupreme]

I remember that line too. The quote on the board is more blunt and says it's not possible. So don't count on an upgrade being available. Also things may have changed now that the 60kWh pack is actually finalized (so they are better able to assess the viability of swappable packs).

Not really 'not possible' but 'not going to happen'. Big difference there. I agree that after they are producing cars with separate packs they have made them more different than they wanted, and thus won't commit to upgrading packs.

 

[NigelM]

Agree that it's the right "company statement" to make. Surprised that it was so blunt, though. No handholding.

Tesla has been criticized plenty on the forums for not being direct and straight.

I think they're implementing this policy because they want people to buy the biggest battery they can afford right now, since that will help their bottom line.

And, if true, that's a perfectly acceptable reason IMO. Long-term financial health is important.

 

[brianman]

Tesla has been criticized plenty on the forums for not being direct and straight.
And, if true, that's a perfectly acceptable reason IMO. Long-term financial health is important.

Would anyone feel better if Tesla had said, "Battery capacity will not be upgradable through Tesla in 8 years because Tesla wouldn't exist financially if we tried to provide that"?

 

[stealthnhawk]

I am planning to get the 40kw but with this now, I am wondering if I should buy Lexus is g3 and wait for 3rd gen. I want to keep car for 10years but I don't want to be stuck at 140mi range while every ev car by then have min range of 200...

 

[Doug_G]

Honestly, I would never recommend anyone get the 40 kWh pack. IMHO the 60 should be the baseline pack size.

 

[DFibRL8R]

The laptop with upgradable components analogy is interesting especially because that is a hot topic now. The latest apple lap tops essentially have become disposable/non-upgradable with a non-removable battery literally glued inside a sealed case. This forces the owner to upgrade to an entirely new device after a few years. I would hope this limited upgradeability is not Tesla's goal though didn't George Blakenship come from Cupertino?

 

[ElSupreme]

The problem with 'upgrading' the battery is that these batteries are REALLY complex. They have thousands of cells, probably hundreds of sensors. Coolant loops different masses, different centers of gravity. It isn't the same as plugging in a slightly larger single (parallel) Li-Ion cell into your cell phone.

Tesla surely would like their cars to be identical except for a hot swappable battery pack. It saves costs making the cars. But I bet it turned out there were more differences than they imagined. And they are not committed to providing all the testing and troubleshooting needed to say you can get a bigger pack if you want it. If they feel they can do it, and there is a market for it I am sure they will. But publicly saying they won't do it is the correct thing to do.

Weren't we all bitching about Tesla not being honest and open enough about 8 weeks ago? You got what you wanted. Well kind of.

 

[brianman]

Weren't we all bitching about Tesla not being honest and open enough about 8 weeks ago? You got what you wanted. Well kind of.

Time for someone to link George's quote about people screaming for transparency until they get answers they don't like.

 

[rcc]

What ElSupreme said.

I'm sure Tesla would like to do a much higher capacity battery pack 8 years from now that would be a drop-in replacement for the current packs. Their engineers may even be confident that they can do it. But the company would be insane to promise that publicly: there are so many variables that they can't be sure they can do it. A lot can happen in 8 years.

 

[Doug_G]

Tesla doesn't even promise features that they already know are going to be added to the cars. See Updated - Interior Lighting - Page 17

So what they're saying comes as no surprise. Nor would it be surprising if this changed sometime in the future. You just can't depend on it.

 

[stopcrazypp]

It's definitely better for Tesla to say that they won't offer it now and then offer it later when they find out it's feasible, than to say they can possibly offer it and then find out it's not feasible later. They might lose some potential customers upfront, but that's better than the latter (which is at the least a broken promise if not false advertising).