Electronics giant Panasonic is spending US$705 million (NZ$1.045 billion) expanding its Wakayama plant in order to produce bigger lithium-ion batteries for Tesla, according to a new report.
The Nikkei reports the facility will be used to make the Japanese company's new 4860 format batteries, which have five times the capacity of those currently supplied to Elon Musk's EV company.
Because of higher efficiency, it's expected each battery will cost between 10 to 20 percent less to produce, while offering a larger range.
Tesla's Model S currently has a range of around 650km on a single charge, but that could be extended to around 750km with the batteries, the report says.
The increase in range, coupled with the decrease in price and the need for less batteries may make electric vehicles cheaper to the general public.
CEO Musk has already said Tesla wants to make its own batteries to supplement the supply it gets from Panasonic and other manufacturers.
The new batteries are expected to be available to Tesla in 2023, according to the report, with enough to power 150,000 EVs made each year in Wakayama.
Meanwhile the Musk-run company has countersued JPMorgan Chase over a disputed contract, saying it was seeking a "windfall".
The bank sued Tesla for US$162.2 million in November, saying the company "flagrantly" breached a contract the two signed in 2014.
"We have provided Tesla multiple opportunities to fulfill its contractual obligations, so it is unfortunate that they have forced this issue into litigation," a spokesperson for JPMorgan said at the time.
The issue surrounds Musk's tweet on August 7, 2018 which stated that he might take Tesla private at US$420 per share, with "funding secured".
That tweet cost Musk and the company US$20 million each in fines from the US Securities and Exchange Commission (SEC).
In the countersuit, Tesla said JPMorgan's lawsuit was motivated by a dislike of Musk.
"JPMorgan pressed its exorbitant demand as an act of retaliation against Tesla both for it having passed over JPMorgan in major business deals and out of senior JPMorgan executives' animus toward Mr Musk," it said.
The company has denied that, with spokesperson Brian Marchiony telling Reuters there was "no merit" to the counterclaim.