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DEVELOPMENT THERMAL MANAGEMENT

FIGURE 1 Thermal management requirements for
vehicles with a combustion engine (© Mahle Behr)

inlet and outlet, and within each of the that the powertrain loses its most impor- When heating (T ambient = 0 °C), about
cells, does not get too large. The quality of tant heat source, the combustion engine. 2 kW of heating power is required to
battery conditioning – or the most homog- Particularly in winter, this presents new maintain passenger comfort in the com-
enous temperature distribution possible challenges to interior temperature con- pact car segment (average drive power
along the cells – is crucial for the perfor- trol, which relates to comfort and safety, required for urban use is around 3 kW) –
mance and service life of the battery. because the thermal management must the crucial segment for electric vehicles.
not place too great a load on the battery This reduces the electric cruising range by
and thus the electric cruising range that about 40 %. Due to the significantly
THERMAL MANAGEMENT
REQUIREMENTS FOR is so important. The low level of availa- higher drive power of about 9 kW and
BATTERY-ELECTRIC VEHICLES ble waste heat must be used optimally practically constant heating performance,
for this purpose. the loss of cruising range in the mid-range
On closer inspection, the step to a purely In a first step, passenger comfort can segment is not quite as drastic, but still
electric powertrain does not simplify be ensured by means of a High Voltage noticeable, at about 21 %, FIGURE 4.
thermal management at all. The number (HV) heater installed on the air side or If the low yet present waste heat from
of circuits is indeed reduced, but the the coolant side without great effort, FIG- the electric motor and power electronics
incorporation of the refrigerant circuit URE 3. This comes at a cost for the cruis- is used in conjunction with a coolant/
for conditioning the Li-ion battery ing range, however, as in both cases the coolant heat pump, the cruising range
remains. What’s even more critical is battery is loaded at 100 %. (at 0 °C) can be increased by up to 20 %

FIGURE 2 Thermal management requirements for
hybrid and plug-in hybrid vehicles (© Mahle Behr)
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