Note On The Smmi Plugs: (Fig.3.15); Thermal Management - Sunrise Medical Quickie Attitude Directions For Use Manual

Note on the sMMI plugs: (Fig.3.15)

If you need to remove the sMMI plugs leading to the battery at
any time, please note the following information when
connecting them again:
• The plug of the sMMI and the socket on the additional cable
to the battery must be correctly aligned when connecting.
• Both parts are a little tricky to connect but this prevents
moisture ingress during operation.
• Do not kink the attached cables at any time when
connecting the plug and the socket. There is a risk of the
cable breaking.

Thermal management:

A combination of three temperature sensors, an intelligent
software control system and patented air circulation ensure the
motor is optimally cooled. In practice this means greater and
longer output on climbs or under high (attachment) loads.
Advantage: protection against premature overheating on long
climbs and high loads – longer support on hills, higher level of
efficiency and thereby a lower battery consumption as the
motor is optimally cooled.
About the theory
As with all drives, gearless wheel hub motors are also
optimised to an operating point consisting of speed, load and
output. Our wheel hub motors are designed for operation in the
speed range between 15 km/h and 25 km/h and a normal drive
output of 250 watts. In this speed and performance range they
achieve the greatest efficiency and range, which means that
the supplied energy is optimally converted into drive energy.
Whenever a motor is operated outside of the optimum
operating point, its level of efficiency decreases. This leads to
the fact that the energy is no longer optimally converted, rather
part of the supplied energy is converted into heat. The range
therefore decreases and the heat needs to be discharged. In
the neodrives motors this heat discharge is achieved via a
large contact area inside the motor (stator carrier) to the
dropout or chain stays of the bicycle frame. In addition, cooling
ribs inside and outside the drive housing ensure the greatest
possible heat exchange with the surroundings. Heat which
cannot be discharged causes the drive motor to heat up.
The neodrives wheel hub motors monitor both the supplied
energy and the temperatures in the motor. This enables
damage to be prevented as a result of overheating in an
overload situation. However this also results in the motor
performance that is accessible by the rider. Being reduced to
prevent overheating.
38
Fig.3.15
If a temperature of 80 °C is exceeded in the motor electronics,
the motor control system reduces the input power and thereby
the support. This means that the higher the temperature
increase in the motor, the less drive output can be accessed
and the lower the support available. When the motor cools
down, the energy input is increased again and the drive output
rises. Important: The motor cannot be damaged by heat build-
up. The temperature symbol (Fig.3.16) only appears when the
power is completely reduced.
Fig.3.16
This regulation of the drive output as a function of the motor
temperature is progressive so that there is always support but
the motor is not damaged by overheating.
In practice
As a result of the points explained above, the day-to-day
practice is dependent on the outside temperature, total weight,
incline, the terrain, cadence, air pressure and speed. These
factors may lead to a temperature being reached which causes
the output or support to be reduced.
However, this does not mean a fault or failure of the drive, you
can continue to cycle at lower support. In an extreme case it
may cause a brief complete shutdown.
Extreme example: An incline of 10 – 12 % at an altitude of 500
metres, a total weight of 120 kg, loose terrain, a maximum
assistance level, a speed of < 10 km/h and a cadence of 60
rpm mean operation in an unfavourable range at low efficiency
and range at simultaneously high heat generation. This will
result in a reduction in the drive output.
Tip: Ideally, by selecting a lower gear with higher cadence, the
travel mode "Tour" or "Eco", a reduced assistance level and/or
a short break (in which the drive can cool down again), you
can continue to cycle.
Attitude/Attitude Hybrid Rev.3.0