Drive Unit Fix

Bosch BES2 Range Extender dongle

Unlike other unsafe range extenders without fuses, cross-charge or thermal protection and amateurish openings in the original battery, we have developed a fully safe, protected activator dongle integrated into the dual battery system.

This module enables you to use any 36V battery with a voltage range of 26V-42V as a dual battery range extender

You can use any type of battery - Li-ion NMC, LFP (LiFePO4), Lithium Titanate, Lead acid, Sodium ion.

The electronics calculate the remaining capacity or range with the same system Bosch uses, every Amp in or out gets counted. This way you can even add over 2000Wh and the display will show you the correct estimated range with both the original battery and the extender battery.

Installation: The dongle needs to be placed in a removable saddle or frame bag of 10cmx8cmx7cm minimum dimensions.

The 3rd party battery should come with an xt60-F female connector. You will need to access the original battery wires, either though the frame, at the motor (can require crank puller) or near the original battery contacts. Anywhere where you can splice into the red,black, green and yellow wires (not from the display!) will do. 

The install takes about 1h depending on your bike. Generally no specialized tools are needed, see manual for instructions.

Charging: The 3rd party battery MUST be charged with the Bosch charger, outside of the bike. This ensures correct range estimates and proper overcharge protection in case the 3rd party battery doesn't protect against accidental charging through the discharge contacts.