Tesla has made a big deal out of its new 4680 battery cell design, claiming it will both increase the range of its vehicles and reduce the cost-per-kilowatt of its battery packs. It's been working on finalizing the design and production process for these new cells at a pilot plant in California, but now, according to a report published on Monday by Reuters, there's a production start date in sight.

Only, it isn't Tesla's 4680 start date that we now know. Instead, it's Panasonic's. Panasonic has long been Tesla's battery production partner of choice, and the Japanese giant will kick off its 4680 production in March of 2024. Tesla is already building Model Ys at its Austin, Texas plant with 4680s from its pilot plant.

The 4680 cell, so-named because its 46 millimeters in diameter and 80 millimeters tall, features several design innovations over the more conventional 18650 and 2170 cells that Tesla uses in its vehicles now. The biggest is that the 4680 is a tabless design that reduces the number of production steps and cuts back on the cost-per-cell, thanks to fewer parts being necessary. The tabless design is also allegedly more electrically efficient, accounting for the claimed 16% range increase.

Panasonic is already cranking out cells like crazy for Tesla and other partners, so this move into 4680 production will necessitate an expansion of its facilities. The company is already planning on adding two new production lines to its Wakayama factory to accommodate.

We reached out to Panasonic for comment but didn't hear back in time for publication.