Musk occasionally responds to direct questions on Twitter from fans, and thanks to one of those enquiries, we now have a much clearer picture of the Roadster 3.0's debut. The company boss indicates that the new battery should be done with its safety checks in July, and he thinks the package should be ready for sale in August.
There's still no word about the price for this progress or whether the changes might allow the Roadster to take advantage of Tesla's Supercharger network. With such a massive boost in driving range being offered, it's hard to imagine the upgrade not being popular among Roadster owners, though.
@bonnienorman New Roadster battery should complete safety validation by end of July, so likely available in August- Elon Musk (@elonmusk) April 23, 2015