Video review of the new LEGO 8878 Rechargeable Battery Box - YouTube
Keybrick One – Keybrick
Technical Moc Parts Power Functions Aaa Battery Box Case Compatible With Legoed 10257 10261 10247 8881 8883 Robot Car - Automation Modules - AliExpress
Compatible with 8878 Power Functions Rechargeable Battery Box 800mAh | eBay
New 8878 Rechargeable Lithium battery Multi Power Functions Tool PF Model Sets Building Blocks Compatible with Lego Parts MOC| | - AliExpress
LEGO has a mysterious new rechargeable battery, what can be the product? - RacingBrick
5pcs Power Functions Battery Box XL M Motor IR Receiver Controlled Set for LEGO | eBay