SMART Fortwo 451 Series Introduction Into Service Manual page 26

The permissible operating temperature of the
high-voltage battery is -25 °C to +55 °C.
The service life of the high-voltage battery is
reduced by high temperatures.
The high-voltage battery is thus cooled by a
coolant circuit under normal operating condi-
tions.
On vehicles with code (V03) Battery cooling
system there is also a heat exchanger with the
refrigerant of the air conditioning system
(chiller) in the coolant circuit of the high-voltage
battery.
The capacity of the high-voltage battery and thus
its power consumption characteristics drop off
heavily at low temperatures. As a result, at
temperatures below 0 °C the high-voltage battery
is heated during charging by a 12 V PTC heater
(high-voltage battery heater) in the coolant
circuit of the high-voltage battery.
The temperature of the high-voltage battery is
recorded by the battery management system
control unit via temperature sensors and
cooling/heating mode is initiated as necessary.
Discharged high-voltage battery
If the high-voltage battery is fully discharged,
the drive system shuts off.
Introduction of smart fortwo electric drive (3rd Generation) • Model Series 451
High-voltage battery
In order to comply with the maximum permissible
air humidity level, a desiccant cartridge is
installed below the high-voltage connection at the
bottom right of the high-voltage battery.
i Note
The desiccant cartridge must be replaced every
2 years or every 40,000 km.
i Note
The drive system can be briefly reactivated once
by switching the ignition off and on in order to
move the vehicle a few metres outside of a
possible hazard area.
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