Software locked 75kWh?

[gregd]

One additional advantage is that a software-limited car is the same hardware SKU as the high capacity one. Software-only options don't change what the manufacturing line produces, so with their focus on simplicity in manufacture, I still think this is a possibility. One might even speculate that the various flavors of software limiting that have occurred on the MS/X products over the years were in some regards preparation for this precise need. It wouldn't surprise me if both battery capacities are offered at launch.

To the concern about profit margin, on these first set of cars (say, for the first quarter), the difference in margin is not going to make much of a difference in the overall financial picture. The importance is getting the manufacturing line automated, refining build quality, and keeping the 400+ thousand reservation holders engaged. Once the volume picks up, they can start adjusting the physical battery capacity to further improve margins.

 

[aronth5]

Not that I believe Tesla will do this but another option is a 75kWh battery software limited to 60kWh with options to add in 5kWh increments. Lets say $1,500 per increment.
That would give Tesla a steady stream of income over the life of an awful lot of owners who would upgrade not once but perhaps 2 or 3 times. Would also help with the car's resale value for those who don't upgrade.

 

[JoRey]

It makes no sense to put a bigger battery on the Model III. Not only are the profit margins much tighter then the S and X. The people buying the Model III are not going to trade in their car for the latest and greatest Tesla. I think Model III buyers are the same consumer base as the Prius back in 2004 and 30% of Prius drivers keep their cars for 10 years. It may however make sense for Tesla to give leased cars an software locked battery and then resale the car at a much better profit.

 

[GoTslaGo]

As @mongo had pointed out, the software locked battery will charge faster and you can keep it topped off at "100%." On a practical level this could work out for Tesla as a whole because it will shorten charging times at the Superchargers. Getting to 60 kWh max on a 75 kWh battery is 80% (75 kWh max on a 85 kWh battery is 88%).

Current owners of software limited 60 kWh models have reported full charging in less than 30 minutes (and getting dinged with idle charges...another thread on that if you look). Depending on your initial state of charge you could potentially see a full charge in 15-20 minutes, or less. This will increase supercharger through-put and hopefully alleviate congestion.

If Tesla rolls out faster superchargers (IIRC now it is 125 kW, imagine 250 kW, if not 350 kW--"child's play as per Elon") then you can see the charging times drop significantly, making a supercharger visit almost akin to going to a gas station (10 minutes tops?). Battery experts please feel free to refute, as there are issues I recall regarding C-rates, etc...

Furthermore, allowing the Tesla to "live" at 100% charge (software limited) would help decrease some of the confusion than many new Tesla owners experience (there are threads about this) and makes its comparable to having topped off your ICE...every night...at home.

So IMHO, the move to standardize to software limited packs would help stream-line production, potentially alleviate future supercharger congestion, and remove some confusion in EV ownership for folks transitioning out of ICEs. Overall, hopefully improving the total Tesla ownership experience. We shall see!

 

[Country Roads]

How much more does a 75kWh pack weigh over a 60? How much would this extra weight hurt in range?

 

[JeffK]

It makes no sense to put a bigger battery on the Model III. Not only are the profit margins much tighter then the S and X.

I'm not sure why people keep saying this... they are targeting 25% margins which are still one of the highest in the auto industry. Sure the Model S/X are now inching towards 30% so technically, yes, the margins on the Model 3 are tighter than Model S/X, but that's irrelevant.

How much more does a 75kWh pack weigh over a 60? How much would this extra weight hurt in range?

Less than the Model S from 60 (non-software locked) to 75 kWh due to less weight for that 15 kWh.

 

[zenmaster]

The people buying the Model III are not going to trade in their car for the latest and greatest Tesla.

What percentage of Model 3 buyers do you think would lease it or trade it in within 3-5 years?

 

[hill]

This is my wet dream here. I'll be able to charge the full 60kw all the time with no degradation . . . . .

the trade off is, you charge at a slower rate. Very few owners see 400mph charge speeds - and some feel it's due to a change in anode chemestry .... old versus new (85kW teslas, versus 90kW). Between the notion that the 1st run of 3's will NOT be AWD, and the confusion of throttling ... we may not get our early 3, but do a wait & see. It would have certainly been better if we'd kept our S, and not gotten the X.

..........snip........ Less than the Model S from 60 (non-software locked) to 75 kWh due to less weight for that 15 kWh.

read some of the old posts. The hacks show you don't get anywhere near 15kWh's on the upgrade.
.

 

[JeffK]

read some of the old posts. The hacks show you don't get anywhere near 15kWh's on the upgrade.

Doesn't matter... point is the upgrade adds less weight than it would have with the Model S and 18650s

 

[mongo]

How much more does a 75kWh pack weigh over a 60? How much would this extra weight hurt in range?

Warning: many assumptions follow:

It depends how the packs are set up. Say the setup is each module is 7.5 kWh, and for symmetry, they are installed in pairs. So a 75 kWh is 10 modules.
What is a 60? In the simple world, there are two choices. Either there are two less modules 7.5*8 = 60, or each module is reduced in capacity 10* 6 kWh= 60.

So which would it be?

From an electrical efficiency point of view the advantage goes to keeping the same number of modules since the pack voltage the same. A high voltage means less current (in the cables) for the same power, so less resistive loss during operation, and also during charging. A high voltage also allows a high motor top speed (torque is voltage/frequency). It also lets all the electronics be the same.

Reducing modules has the potential advantage that you could pull the top off a pack, add in two modules and convert a 60 to a 75. But I think that is an extreme edge case.

So with pack physical size fixed (based on mount points/ overall vehicle structure), and the number of modules fixed, the only variable is how the reduced capacity modules are made. The simplest from a thermal/ commonality point of view would be to use dummy cells. These would have the same outer can, but no active internals (possibly a filler for strength).

Based on this line of thought the weight difference would be the delta between an active cell vs an dummy cell * number of cells.

The 85 kWh pack was ~1200 pounds, so I'd guesstimate < 100 pound difference (or in ICE terms, 16 gallons of gas).

 

[Garlan Garner]

Looks like no lock.
Tesla accidentally reveals Model 3 efficiency hinting at impressive range