piece information - Classic 9V battery box current limiter? - Bricks
Lego 8878 Power Functions Rechargeable Battery and 8887 Transformer - YouTube
Lego Battery Box Mod - YouTube
How do I open this battery box? YouTube is not very helpful. Part no. 2847 : r/lego
How to modify your Lego Technic Battery Box. Save on Batteries! More Power! - YouTube
How do I open this battery box? YouTube is not very helpful. Part no. 2847 : r/lego
Train Battery Box Car with Three Contact Holes, Black Switch Lever, Black Magnets, and Black Wheels with 'DB 7722' Pattern on Both Sides (Stickers) - Set 7722 : Part 3443c07pb01 | BrickLink
Amazon.com: MingCheng Upgrade Kit Motor Set Power Functions Motor, 11 Pcs Power Functions Motor Set for Lego Technic Power Kit, 4 L Motors, 1 Steering Motor, Battery Box and Remote Control :