2019.16.x rambling speculation (all based off of internet forum lurking): Looks like in 'some' of the Model S 85 kwh vehicles there is a problem with a module. (there are 16 modules in a pack, 6 bricks in a module, 74 cells in a brick (pack is 96s74p). In order to preserve the module (and thus, the pack) . . Tesla is issuing software updates that limit the pack .. those limitations include: - lower pack capacity -- i.e. lower max cell voltage (thus pack voltage) (i.e. maybe 4.1v/cell instead of 4.2v/cell) - lower supercharger speeds - less brake regen - less acceleration Also appears that the 'bad' (or getting bad) modules cannot be feasibly replaced. (too hard to find matching modules to keep the repaired pack balanced, plus it's beyond the scope of the SCs.) So I wonder if Tesla could develop a fix that would "clip" the bad module ... but this would probably be a fair amount of work, .. possibly have to change out some of the BMS(?) and, of course, would result in a pack that will not perfom like when new (i.e. .... it had 16 modules in series, repaired would only have 15 -- lower max pack voltage, less acceleration, lower range) ** add -- I would think this is along the lines of a recall, and might involve some sort of payout to the affected owners as well,.. the way it stands the software route is just buried in the category of ""normal"" degradation. /can't find much about why a module would be singled out as bad ... perhaps it has a hot spot .. extra resistance due to circuitry, .. bad cooling ...I dunno(?) // no idea how widespread the problem is, how many vehicles are affected ///take all of the above with a huge cup of salt (lurking has its limitations),..