No Battery Upgrade With Replacement Program

No Battery Upgrade With Replacement Program

I've seen multiple people on here talk about getting the 40 and then upgrading to a larger battery pack down the line using the battery replacement program TM released. I was told today by TM that it wouldn't be possible. They cite engineering differences per different packs and encouraged me to choose the pack for my needs now and in the future.

Sudre_ | January 9, 2013

There are several different answers for multiple questions but I guess you have to take this one for what it is. I don't see the Model S being worth 10 cents 5 to 10 years from now if you can't upgrade your battery to something close to the 500 to 1000 miles they will be getting.

The only reason I see their answer as a flat out piece of deception is a larger battery pack, no matter how much larger, will not put out more power than what the motor is programmed to request. So if you did upgrade your distance will increase but your 0-60 and charge time will not.

I wish people would stop just saying "I was told today by TM....."
Next time get a name. "Fred Bower at TM service center in .... told me ....." because if this turns out to be true I want to ask Fred my questions. If this info is false and Fred is just trying to increase profit for TM I want him FIRED.

sergiyz | January 9, 2013

The battery size/capacity will affect car weight and weight distribution, potentially suspension elements or/and tuning.
Even as of about 2 months ago they weren't sure how to deal with this since they were only installing 85kwh batteries at the time.
What the rep should have said is that they don't know at this point whether the upgrade is going to be possible.
Same goes for newer batteries.
They don't know what they are going to look like and whether or not it will require changing the design of the battery tray, how and where they mount it etc.
It would be very careless for them to commit to anything at this point.

Ceilidh | January 9, 2013

I don't think that the issue here is if the Tesla Model S will be able to upgrade the battery in the future, but rather if the battery replacement program that Tesla is offering with current Model S purchase allows for this option in the future. I had heard through the grapevine (no names) that the program does not allow for this.

I see this as unfortunate. In fact, it is the reason I will not be participating in that program / purchasing that option. To me, the battery replacement prepayment is really only a discount if you can apply your prepayment to whatever upgrades to batteries may occur over the next few years, while simultaneously hedging if the prices skyrocket for some reason. Otherwise to me this is a sill waste of money.

Just MHO.


ChasF | January 9, 2013

I would think that to allow battery upgrades via the replacement program would undercut Tesla's revenue models. They would want you to buy a new car in 8 to 10 years rather than cashing in on the "insurance" and essentially getting another 10 years out of your current car. Of course they are going to discourage that.

I'm not a Tesla engineer, but I am an engineer and I can say with a fair amount of confidence there is very little in the way of engineering obstacles that would prevent a future upgrade, albeit may have to be done by a third party. If the suspension and tuning were so sensitive to the weight difference of a future battery pack, then you'd have to be careful of loading up the car with more than a couple of your 200 lb buddies and tailgating gear in the frunk on the way to a weekend ball game.

If you want to upgrade the battery in 8 years, I think there will be a few option available. Technology is not stagnant.

jat | January 9, 2013

@Sudre - can you upgrade the battery capacity of your 10-year-old laptop? I haven't been able to. I was able to upgrade RAM (to a point), and replace the HDD with SSD, but the upgrades available were pretty limited. I wouldn't expect the Model S to be any different -- they probably won't even be making the Model S any more at that point (at least not as it exists today), so expecting them to spend engineering effort on creating new things for it instead of their shiny new model seems unrealistic. I will be happy if they are still making replacement battery packs exactly as they are now.

@Ceilidh - the prepaid battery replacement is simply insurance for those that are worried about it, nothing more or less.

TimJ | January 9, 2013

Along the lines of what @ChasF was saying, the purchase the battery now option allows Tesla to earn interest on the cash that they are holding now for your future batter that will cost less at a future date. You can't switch between the batteries in the program because they cost different prices and allowing you to switch undercuts their financing metrics. Also, with that program, they are probably accounting for using your old "core" and recycling part of it.

ChasF | January 9, 2013


Of course it would be different. Yes, it is theoretically possible to upgrade the battery in your 10 year old laptop, it just isn't worth the several hundred dollars to do so, thus, no market exist for this type of upgrade. But saving several thousand $ by upgrading your Model S battery pack vs buying a brand new betcha there will be a market for that!! You'll have guys coming out of the woodwork with mod kits to cash in on that action.

jat | January 9, 2013

@ChasF - I can still buy original battery packs for my 10-year-old laptop. I think it would be much simpler for them to offer higher capacity batteries for a laptop (which involves just some injection molded plastic) than to have the tooling to build Tesla battery packs, which are actually a structural component on the car.

Anyway, it is pointless to speculate about it now, but personally I am not relying on any future upgrade to the battery. If it happens, then great, if not then I got my money's worth anyway.

ChasF | January 9, 2013


"If it happens, then great, if not then I got my money's worth anyway."

True. Can't argue that.

Brian H | January 9, 2013

Lots of issues conflated here.

There are distinct differences between 40 & 60 & 85kWh cars aside from battery size. They won't change if you plug in a different battery.

Elon "promised" this capacity up front long ago, and mentioned it more recently, but it's not a business issue or worth TM tooling up for yet.

Speed would change with the battery; the motor, short of the performance model, is the same. Supercharging would either be available from first purchase, or not.

The first moment of truth will come when a 40 owner offers to prepay $12K for an 85 replacement 8 yrs down the road.

Interesting note: a 60 owner could buy a used 85 for cheap and get 60 kwh, with a much slower remaining "decline rate" than a new 60kWh battery's.

pvenkate | January 9, 2013

It was mentioned in one of the blogs that the 3 battery packs were expected to be identical structurally and in weight, but I cannot attest to whether the same electronics/inverter/motor combo are able to work with any of the 3 battery packs (I'm thinking, no). So, unless the latter can also be easily upgraded along with the battery pack, I think this issue is moot.

However, from a resale value perspective after 8+ years, the ability to swap out your depleted battery pack to a new/used pack of at least the same capacity, is very important and Tesla has taken care of that.

jat | January 10, 2013

@pvenkate - The 85kWh and 60kWh has the same number of cells, so presumably they will weigh about the same - the difference is the 85kWh uses 3.1Ah cells while the 60kWh uses 2.2Ah cells. The 40kWh battery uses 4700 (instead of 7000) 2.2Ah cells, so it should weigh less.

JThompson | January 10, 2013

Hard to believe there is even a thread on battery replacement for a car that has been in production only 6 months!

Timo | January 10, 2013

It is very expensive part of the car and battery degradation over time is known fact, so anybody planning to get one would like to know if you can get battery replacement and if possible the price of the replacement (price is very difficult to predict, too many variables).

Speculations are good thing as long as you realize that they are just speculations.

Sudre_ | January 10, 2013

jat, Tesla has to have some kind of spare parts for the car for a certain number of years. There will be all three batteries at a minimum. Again I am not saying Tesla will offer an upgrade from 40kWh to 85 kWh with no change in acceration and a slower charge time. I am just saying that if they don't the resale value of the car is the same as my 2003 destop computer. $10.

As far as offering battery upgrades for Laptops, I have never heard of a laptop that you can buy that came with the option of three different battery sizes. If it did the average hacker would tell you the only difference would be a few bios changes and maybe a new charge for $20.

Timo | January 10, 2013

As far as offering battery upgrades for Laptops, I have never heard of a laptop that you can buy that came with the option of three different battery sizes.

I have. Some time ago it was quite common thing to have "power battery" option with a bit longer battery life. Usually quite heavy things, drag-able more than portable.

Sudre_ | January 10, 2013

Great timo then do you know if after purchasing the laptop were you able to buy the extended battery afterward or did they male you buy a whole new computer? All I know is five years after owning my Toshiba I went to Batteries R Us and they sold me a nice third party battery replacement.

stephen.kamichik | January 10, 2013

The 40 kWh battery would satisfy my current needs. I am getting the 85 kWh battery so that I do not have to worry about battery life. Take the battery replacement money and buy Tesla stocks.

archibaldcrane | January 10, 2013

I think it's a bit optimistic to just assume that there will be 500+ mile range electric vehicles (or, more specifically, 160kwh batteries for personal vehicles) 8-10 years from now.

Look at EV history - the EV-1, Rav EV, Leaf and Focus Electric all have around the same range, give or take 20% - and that's over a 14 year "development" range from oldest to newest.

The cost to weight to demand ratios aren't going to change as much as people think. If anything the cost on larger, tesla-sized batteries will come down some and be put into more, cheaper cars, but I doubt Tesla or anyone else will have an EPA-rated 500-mile range vehicle of any sort on the market 10 years from now. Battery tech just doesn't evolve that quickly and there isn't enough demand for an EV that can drive 8 hours straight at freeway speeds without charging.

murraypetera | January 10, 2013

I do not know how accurate this information is but early on (year back at an open house) I was told by local tesla reps in NYC that the 40,60,85 cars were identical in every way other than the battery capacity and I asked if I were to upgrade at some point to a larger pack from 40 to 85 would I get the acceleration of the current 85 and the answer was yes.

I am sure that the acceleration limits are controlled in software. The battery packs are designed to be drop in quick change so moving from 40 to 85 or 160kwh should be unbolt, drop away and pop in the new. The car should know how big the pack is by asking it and acceleration, etc. should automatically be adjusted.

archibaldcrane | January 10, 2013

Take anything a tesla rep tells you with a mountain of salt. They are rarely quoting official Tesla policy.

Sudre_ | January 10, 2013

I kind of get it now. I was not realizing that they are saying the battery can't be upgraded with the replacement battery program. If you pre-buy a battery you get the exact same battery you started with. I would expect that. They are sell those batteries at what they think will be bargain prices.

If you do not per-purchase a battery then I would think you can spend all the money you want to upgrade the car however you want.

ChasF | January 10, 2013

"Look at EV history - the EV-1, Rav EV, Leaf and Focus Electric all have around the same range, give or take 20% - and that's over a 14 year "development" range from oldest to newest"

@archibaldcrane - Using past history is not a good metric for speculating on future EV battery tech. 14 years ago there may have been only a few hundred electric/hybrid cars on the road. Today, there are thousands. 10 years from now there will be 100s of thousands (based on current trends). That alone will accelerate EV battery development at a much faster rate than we have seen before. Therefore, it is not unreasonable to expect a 500 mile battery in 8 - 10 years. There is a market for it now, it's just that they are currently still too expensive.

jamestily | January 10, 2013

I think that the motor may be slightly different in each battery size. If you look at the specs, the horsepower and torque numbers are at different rpm ranges. Maybe the inverter is also not the same.
That would explain why cost increase from 40 to 60 to 85 is $10,000 to each capacity now, but $2000 with the replacement battery. Also, the larger the battery, the more it weighs, so the suspension would have to be designed to match.
I configured with 60kwh because that is what I need. I could see being able to get a small increase in range with a replacement battery in about 8 years due to improved technology, but not an upgrade to a larger heavier battery.

Vall | January 10, 2013

It is entirely possible to change a laptop battery with a bigger one. IBM ThinkPad used to come with a 6-cell battery, but there was an optional 9-cell, which was protruding at the back of the laptop, and you could buy it at any time. In every batter pack for laptops there is a small circuit that keeps track of battery performance. That is how you can go into the properties of the battery (in windows or linux) and see that the cells are made by sanyo or panasonic or whatever.The battery also "knows" its design capacity, that's how you can see the "life" of the battery, in percent. If it says 80%, it knows that because if the batter had a design capacity of 100wh, and the terminating voltage was reached after only 80wh were put in the battery, it estimates that the battery has lost 20% of the capacity. And if capacity falls below a certain threshold, you get a warning to replace your battery. That is why the same battery will show the same capacity even if put in different laptops. It would simplify tesla's task of changing batteries a lot if their packs have a similar system inside, which communicates with the car electronics, so maybe they have one (maybe not). So if the motors are the same, most likely the inverters are the same, as it would be a hassle to have components with lower power rating for the smaller packs. I could be also that the settings for each battery are programmed in every car, and it loads the correct firmware after detecting the type of battery. So it should be technically possible, especially if it is true that all the cars will weigh the same in order to avoid crash testing all of them...