The 'official' maintenance manual lists to model numbers, "NKDU 10" and "NKDU 10R" as optional equipment in the supplement index. This aircraft shipped with a Becker 3201 so it should also have shipped with the NKDU 10R battery, but the page for the battery "maintenance and operation" is missing. Neither battery appears to be in production anywhere these days. It's not listed on EASA either, I checked.

I did look through some of the reported fires before I asked about this. With a battery box, fuse and the correct hardware the risk for an aircraft that cannot recharge the cells in flight is almost non-existent.