Tesla has been trying to keep the information under wraps but it was recently leaked that Japanese electronics company Panasonic will supply the batteries for the upcoming Model S sedan. With regards to the current battery supplier for its Roadster model however, there isn´t much information out there except that the supplier is Japanese.
Tesla presently builds a Roadster model that uses lithium-ion laptop batteries wired together to create one big battery capable of propelling the Roadster for around 250 miles.
No information on the battery supplier is known, other than that the company is Japanese. Tesla has retained Panasonic for the second model, the Model S. As we´ve said, the available information is far from complete.
It is unknown if the Panasonic-supplied lithium-ion battery will continue to have laptop batteries wired together. It's a possibility that it will be totally different; some are guessing that it could be a specific automotive battery pack.
What we know for sure is that the battery going into the 230-mile and 300-mile range Model S sedans will use 8000 cells instead of the 6800 cells in the Roadster's battery.
To avoid unnecessary weight, the same number of cells will power the Model S for 300 miles and for 230 miles. They do this simply by using better battery cells for the 300-mile range Model S.
The Model S with a 160-mile range comes with a 5500 cell battery pack. The Model S became possible due to a $365 million loan received from the U.S. Department of Energy. It is anticipated that the Model S will be in production by late 2011. The vehicle will be priced at $57,400 but will be eligible for the $7500 federal tax rebate.