Panasonic and Tesla Motor are broadening their battery partnership to include the manufacture and marketing of storage batteries for homes. They will be built at the Gigafactory and boost that plant's capacity utilisation.

Following its plans to acquire SolarCity, it also plans to cooperate with Panasonic on making residential solar panels in New York state.

Tesla and Panasonic will make the storage batteries at Tesla's planned Nevada Gigafactory.

The Gigafactory will begin serious production in November and reach full operation in 2020. Although the main role of the Gigafactory is to make batteries for Tesla's upcoming Model 3, the two companies now also plan to use the facility to make residential storage batteries, starting sometime in or after 2017.

By teaming with Panasonic the goal is to develop products with greater storage capacity that can be manufactured more efficiently, to lower prices even further.

Tesla said in August that it has reached agreement to purchase SolarCity for US$2.6bn to create what it maintains is the world's only vertically integrated sustainable energy company.