I have a theory what could be the big announcement at the Thursday's press conference, aside from improvements to the Energy App that I described in my previous post (this part was covered in Elon's tweet about range anxiety).
This CNBC interview with James Albertine of Stifel has some very interesting information about the Thursday’s press conference. Here are the significant quotes:
(About Thursday’s press conference) “I think this is very important opportunity for Tesla to draw attention back to
where they stand, from competitive stand point, with regards to range.” “When we were at the factory last week, one of the things we saw was
transition from the 4[SUP]th[/SUP] generation to the 5[SUP]th[/SUP] generation of battery cell production technology. We think that they are going to show that they further extended their leadership as it relates to range.
Quite frankly we think that this is most important catalyst for 2015.
Here is my interpretation what was said in this interview.
- I think that transition from the 4[SUP]th[/SUP] t0 5[SUP]th[/SUP] generation of battery production technology relates to transition from D version of battery packs to E version. For those not familiar E version battery packs started to ship around December (VINS of approx. 56,000)
- According to this TM thread E battery packs maintain high (higher than earlier variants of the pack) charging rate up to a higher state of charge. One explanation for this would be that TM tweaked composition of the battery so it can take higher charging rate longer. The other is that E-battery has bigger capacity than the previous variants.
So it seems that, similar to how they retrospectively released information about the auto-pilot hardware, TM shipped all cars with E pack with a slightly bigger battery (same 7104 cells but each having about 10% higher capacity). Utilization of this additional capacity will be enabled via a software release.
The reason that James Albertine assigns such significance to this, I believe, is that for D cars the range could be extended to hit symbolically important 300 miles EPA. I think that this will be accomplished via combination of increase capacity of the battery (additional 27 miles) and improved efficiency of the control of power electronics (via software changes) as well as improved efficiency of the motor, particularly at very low power consumption levels as in coasting (additional 3 miles of range). so the total EPA rating would be 270+27+3=300.
There is some level of speculation involved in this (on my part, as I believe James Albertine was not speculating, but pretty much conveyed the facts as he knows them), but the potential impact of hitting the 300 miles of EPA range could be very significant (the most important catalyst for 2015 in Albertine’s analysis).