This is a long time lurker's first post … be gentle! I have a Roadster 2.5 due to arrive in a few weeks time, and I'm counting the days. Below are a few questions that I'm curious about to which I cant find answers from older threads, although I can see the subject area has been discussed before.
One thing offered to me at purchase time was the $12k / £9k payment for whatever future ESS replacement solution Tesla Inc might have, if/when the existing ESS keels over, hopefully at well over 100,000 miles time. They hint that a replacement ESS may be something quite different from the existing unit.
Meanwhile, I'm developing a consumer electronic device subject to patent that uses high capacity 18650's, and energy storage is something I'm very interested in generally. I am aware of rapid developments in energy storage research including things like Lithium Air based cells, Graphene based ultra-caps, and other emerging possibilities, all of which hold out the promise of 500 to 1000+ miles 'range' in 5-10 years time …
So, what is possible with an ESS upgrade right now ? …
The ESS uses #6831 x 18650 cells from Panasonic rated at a nominal 2.1Ah, and was designed / developed / refined between 2005-2006, or thereabouts.
Since 2010 Panasonic have been able to supply 18650s rated at approx 3.0Ah.
According to their datasheets, the two cells have identical thermal / electrical characteristics and current cutouts for the same load conditions with the only difference being that the energy capacity is +40% and the charging profile is different to the original cells, and the car would take longer to charge. If the cars performance / power demands remain the same spec, then surely all the thermal controls and SOC monitoring will be, broadly speaking, the same.
If Tesla offered upgrades to the ESS with newer cells it would allow them to claim a headline grabbing genuine 300+ mile ability for the Roadster … or even 400miles if the forthcoming 4Ah cells are use.
If enhancements like this were announced to support the 'older car', combined with all the Model S PR and its 320mile range, then surely the range anxiety arguments from the ICE industry all start to look a bit weak ? ( And both my last ICE cars could not average more than about 280 miles on a tank full… with only 140miles if I hammered them everywhere!)
So :-
(1) Does anyone know if the existing Roadster software has the hidden-facility to initialize and balance an entire ESS fitted-out with a set of new higher capacity 18650's ?
(2) Do you think that the existing software (or via an upgrade) allows for altering the charge profile for slightly different cells?
(3) Do you think that as Roadsters fall out of warranty in the years ahead, that a 3rd party support network will form offering a reverse engineered ESS cell upgrade ?! (and hopefully not as a result of Tesla going belly up - I've just bought shares too!)
Can anyone offer some insight on the above ?!