EBikeit E90 Owner's Manual page 6

Illustration: The 9v Lithium­ion battery.
On/Off switch to the left hand side. Red light indicates ON
Rear Charging Port (Yellow dust/water cap) on rear.
Battery­test LEDs on top face.
BMS cannot be seen, located inside the unit.
Charging point face is at the REAR when fitted.
The Battery Management System (BMS)
This small piece of electronics is mounted inside the battery case. At no time should you attempt
to open the battery case. The job of the BMS is to balance the charge between the cells (there
are 12 cells in a 36v battery) and prevent the battery from excessive discharging. Unlike many
electronic gadgets, the BMS is designed to look after the battery, so as you ride it won't feel like
the bike is slowing or losing power. What will happen is that battery will cut off and you will lose
power. Very rarely a BMS and controller may cut power to protect the system. This is most likely
because of throttle abuse!. The E90 is designed to feed power to the system using a sort of
short ramping up of power rather than a sharp off and on. When you turn the throttle on the E90,
you'll notice for a short moment that the wheel ramps up power. This is to assist the BMS and
controller in optimising performance, and to feed power to the motor to prevent sudden spikes in
power or jerking the rider forward.