LEGO has a mysterious new rechargeable battery, what can be the product? - RacingBrick
Batteries and Battery packs
LEGO PART 84599 Battery Box, Power Functions, with Dark Bluish Gray Bottom [ Rechargeable] | Rebrickable - Build with LEGO
DooQi CADA Technik Power Function Kit for Technical Cars, Including 3 Motors, LEDs, Battery Box and 2.4 Ghz Remote Control (Compatible with Many Models Such As Lego CADA) (S059-001)
LEGO Creator Power Functions Rechargeable Battery Box (8878) for sale online | eBay
LEGO part 87513c01 - Light Bluish Gray Electric 9V Battery Box Power Functions (Non-Rechargeable) with Dark Bluish Gray Bottom at BrickScout
Pkpower Adapter Charger For LEGO 8878 Power Functions Rechargeable Battery Box 731698070944 | eBay
Power Functions 88000 Battery Box 8883 M-motor Electric Train For LEGO Block Toy | eBay
Technical Parts - 850mah Box 8878 Moc Building Blocks Toy Kids Parts Diy Bricks - Aliexpress