The Powerwall, Tesla's stationary battery system for residential use which sold out in less than a week when first announced, has barely begun showing up in the wild that we're already hearing rumbling about version 2.0. As reported by Electrek, Elon Musk mentioned during an event in Paris: "We are coming up with the version 2 of the Powerwall probably around July or August of this year, which will see further step changes in capabilities." He didn't give much detail, but his word choice is interesting. A "step change" is not just an incremental improvement, but rather a more abrupt jump forward.
But how much of a jump will it be?
It'll be interesting to see which parameters the company has chosen to improve most. For example, you could get Powerwall with the same storage capability but at lower prices, or similarly priced units that have more capacity. Or maybe it'll be the number of cycles before there's deterioration of performance that goes up. Chances are, it'll be a mix of all these things.
Last fall, Tesla Energy moved production of Poweralls to the partially finished Nevada Gigafactory, assembling them from batteries that come from Panasonic, their main supplier. But starting the second half of 2016, the Gigafactory should start producing Tesla's own batteries (still in partnership with Panasonic), which should be better and cheaper than Panasonic's current cells.
This timing is probably not a coincidence. The Powerwall Version 2.0 is probably designed to use Gigafactory batteries. In facto, demand for these stationary battery systems - not just residential but also for utility/commercial use - are probably factored in Tesla's plan to ramp up Gigafactory production enough to get economies of scales, and thus lower costs, by the time the Model 3 starts rolling out.