KINOKAWA, Japan, Sept 9 (Reuters) - The energy unit of

Japan's Panasonic Holdings ( PCRFF ) has finalised preparations

for the mass-production of its 4680 electric-vehicle batteries,

the company said on Monday, as it seeks to start supplying the

cell to automakers.

Panasonic Energy's renovated plant in the western prefecture

of Wakayama will serve as the main factory for producing the

cells, which the Tesla supplier says have five times

the capacity of its smaller 2170 cylindrical batteries.

The bigger 4680 cells will allow automakers to extend the

driving range of electric vehicles and use fewer cells to

achieve the same battery pack capacity, Panasonic Energy said in

a statement.

The company held a ceremony to mark the completion of

preparations to start mass-producing the batteries and showed an

inspection line where trays stacked with the silver-coloured

cells could be seen running through.

The company has sent samples of the 4680 batteries to some

of its automakers to which it is already a supplier and intends

to kick off production of the new cells after getting the green

light from them, a Panasonic ( PCRFF ) spokesperson said.

The company had previously said it planned to start

production of the 4680 cells in the first half of the current

business year that started in April.

The Wakayama plant is expected to employ roughly 400 staff

in the development and production of the new batteries by March

2025, and serve as a site for trying out processes that it could

implement at other battery factories around the world, the

company said.

Panasonic Energy already makes 2170 and 1860 cylindrical EV

batteries at its Suminoe and Kaizuka plants in Japan.