Original Upgrade External Battery For Ninebot Es1 Es2 Es4 E22 E22d E22e Smart Electric Kick Scooter Extra Battery Parts - Scooter Parts & Accessories - AliExpress
Ninebot ES Series, E22 Series, E45 Series Second Battery Pack
How to Install/Replace the External Battery on Ninebot ES1/ES2/ES4, E22, E25 and E45 Scooters - YouTube