BMW I01 Product Information page 93

I01￿High-voltage￿Components
5.￿High-voltage￿Battery￿Unit
Index
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During￿cooling￿the￿battery￿cells￿emit￿heat￿energy￿to￿the￿refrigerant.￿While￿the￿battery￿cells￿are￿cooled
down,￿the￿refrigerant￿is￿heated.￿The￿EKK￿compresses￿the￿refrigerant￿again￿and￿in￿the￿capacitor￿it
returns￿to￿a￿liquid￿state.￿As￿a￿result,￿the￿refrigerant￿is￿once￿again￿able￿to￿absorb￿heat￿energy.￿This￿way
the￿maximum￿cooling￿power￿of￿about￿1000 W￿can￿be￿generated.￿In￿other￿words:￿A￿heat￿output￿of￿up￿to
1000 W￿can￿be￿discharged￿by￿the￿high-voltage￿battery.￿This￿maximum￿cooling￿power￿is￿only￿required
at￿a￿very￿high￿ambient￿temperature￿and,￿at￿the￿same￿time,￿a￿high￿drive￿power.
In￿order￿to￿cool￿battery￿cells￿using￿refrigerant,￿there￿is￿a￿heat￿exchanger￿located￿below￿the￿cell￿modules
which￿is￿made￿from￿flat￿aluminium￿pipes.￿They￿are￿connected￿to￿the￿internal￿refrigerant￿lines￿and
refrigerant￿flows￿through￿them￿during￿cooling.
Heating
Vice￿versa,￿if￿the￿I01￿was￿parked￿outside￿for￿example￿for￿several￿days￿at￿temperatures￿below￿0 °C,￿it
makes￿sense￿to￿heat￿the￿battery￿cells￿before￿departure￿and/or￿to￿their￿optimal￿temperature￿level.￿They
then￿deliver￿their￿full￿power￿before￿the￿journey￿commences.￿The￿customer￿can￿use￿this￿option￿if￿the
vehicle￿is￿connected￿to￿the￿power￿network￿using￿the￿charging￿cable￿and￿the￿function￿for￿the￿interior
air￿temperature￿control￿of￿the￿vehicle￿was￿selected.￿In￿order￿to￿warm￿up￿the￿batteries,￿the￿high-voltage
system￿is￿activated￿and￿electrical￿current￿is￿sent￿through￿a￿network￿of￿heating￿wires.￿This￿network￿of
heating￿wires￿is￿arranged￿along￿the￿coolant￿ducts.￿As￿the￿coolant￿ducts￿and￿the￿cell￿modules￿touch,
the￿heat￿generated￿in￿the￿heater￿coils￿is￿transmitted￿to￿the￿cell￿modules￿and￿therefore￿the￿battery￿cells.
5.4.￿Internal￿structure￿of￿the￿high-voltage￿battery￿unit
The￿information￿on￿the￿internal￿structure￿and￿other￿functions￿of￿the￿high-voltage￿battery￿unit￿can￿be
found￿in￿the￿product￿information￿bulletin￿"I01￿High-voltage￿Battery￿Unit".
A￿repair￿of￿the￿high-voltage￿battery￿unit￿is￿only￿intended￿in￿a￿dealership￿with￿the￿Service￿format￿"BMW￿i
Extended￿Battery￿Service"￿or￿"BMW￿i￿Full￿Service".
Explanation
Heat￿exchanger
Blower￿for￿passenger￿compartment
Combined￿expansion￿and￿shutoff￿valve￿in￿the￿refrigerant￿circuit￿(for￿cooling￿the
passenger￿compartment)
Evaporator,￿passenger￿compartment
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