MAHLE Smartbike Systems X35 SP1 External Ebike Battery/Range Extender - Battery Holder Cable Retention Straps

The Mahle X35 SP1 Range extender battery provides 36V/208Wh of additional power bringing the total capacity to 450W for the X35 drive system. The Range extender includes a holder that mounts to the water bottle bosses on the frame. It charges the main battery while riding and offers a parallel power supply to the motor when the power draw exceeds 2A.

36V 208Wh Panasonic

BUS Compatible (Smart) Balanced operation as charger or independent battery

The Mahle charger will recharge both the main and range extender batteries at the same time