In a Tuesday interview with Bloomberg, the head of Panasonic's Automotive Division said that the company was on track to complete an additional three battery-cell production lines at Tesla's Nevada Gigafactory before the end of this year. That puts the expansion ahead of schedule for completion.

Panasonic is a joint owner of the Gigafactory. The company provides the "2170" battery cells that go into a Model 3 battery pack. Tesla packages those cells to complete the pack.

In the interview, Panasonic automotive executive Yoshio Ito told Bloomberg that "the bottleneck for Model 3 production has been our batteries."

Ito added, "they just want us to make as many as possible."

In truth, bottlenecks around Model 3 development have popped up everywhere along the line, so if they exist in a lack of battery-cell supply (which Panasonic executives have previously alluded to), they are not exclusive to that domain. For example, in January, Ars wrote about a bottleneck that had existed in December 2017 when "Tesla and Panasonic workers were manually assembling bandoliers, rows of lithium-ion cells glued on either side of a cooling tube." That bottleneck has reportedly been sorted out with improved robotics. Bottlenecks have been reported on Tesla's Model 3 factory lines in Fremont, as well.

Tesla claimed in April that some of its bottlenecks were smoothed out by equipment upgrades on its factory lines. Musk has also blamed bottlenecks on over-automation, as well as over-generalization of the manufacturing process.

In short, more battery cells rolling off more lines at the Gigafactory are good for Model 3 production only if the manufacturing process gets smoother. There's evidence that this is happening, as the company was able to sell more than 28,000 Model 3s in the second quarter of 2018, albeit at the slight expense of Model S and Model X production.

The three new Panasonic lines will bring the number of cell-producing lines up to 13, Bloomberg wrote. Ito told the news service that Tesla is currently using all of its Gigafactory capacity to produce vehicle batteries, despite initially planning to reserve 30 percent of its capacity to build stationary storage batteries like Powerwalls and Powerpacks. That has played out in long-delayed Powerwall installations.

Panasonic has been largely positive about its relationship with Tesla: the company said in July that it would invest more in the Gigafactory, if asked. Tesla and Panasonic are also co-owners of the Gigafactory in Buffalo, New York, which recently started pushing out solar panels. It has been reported that Tesla is also facing bottlenecks at that factory, but Panasonic is reportedly able to sell the solar cells Tesla can't accept to other buyers.