"We've got the Tesla Powerwall and Powerpack, which we have a lot of trials underway right now around the world. We've seen very good results," said Musk during a talk to Tesla car owners in Paris on January 29th. "We'll be coming out with version two of the Powerwall probably around July, August this year, which will see further step change in capabilities."
Elon Musk: Powerwall version two is coming in 2016