Project

For the battery pack sizing, carry out the case study of an electric motorcycle to analyze its behavior and performance. The motor requirements of the two wheeler are 40 kW, 110V. The system characteristics can be achieved by analytical calculations and data acquisitions from similar product datasheets:-

• Given that the average peak power from the battery would be 23 kW, choose the type of cell for this type of requirement and state its advantages. Explain the assumptions and thermal components used for the cells.

Answer - As we are working, for a 110V/ 40Kw power pack and average peak power in only 23 Kw we need not to go for a very expensive Battery pack .Also BMS system could be much simpler then as in Car .

• Look for a relevant datasheet and note the cell nominal capacity, dimensions, weight, nominal voltage, internal resistance for the chosen cell.

Answer- Only for ref taken from NET

Nominal Capacity 12Ah
Charging Voltage 54±0.15V
Nominal Voltage 48V
Charging Method CC-CV (constant voltage with limited current)
Charging Current
Standard charge: 0.2CA Rapid Charge: 0.5CA
Charging Time
Standard charge:5 hours, Rapid charge: 2 hours
Max. Charge Current 5A (ambient temperature 25°C)
Max. Constant Discharge Current 15A (ambient temperature 25°C)
Discharge Cut-off Voltage 30V
Battery Cell Panasonic 3.7V 2900mah
Suitable motor power Within 1000W
Operating Temperature Charge: 0 to 45 °C Discharge:-20 to 60°C

• Calculate the total battery pack voltage, current. Find the total number of cells for the battery pack. Also calculate the maximum power transfer from the battery.

Answer - Need more help from mentor.

• Estimate the volume of the battery pack(BMS, conductors can be excluded).

Answer - Need more help from mentor.

v.) Estimate the weight of the battery pack and its total energy.

Answer- Weight should be less as this battery pack is to be used in a two-wheeler Max weight could be 4~6 Kg.

vi.) Define the cell-to-cell interconnection method to be used here.

Answer - Depends on battery pack supplier interconnections could be a combination of series and parallel connections

vii.) What are the tests that you would perform for the battery mechanical stability and safety?

Answer –

• Charging and discharging
• SOC
• Thermal temperature range
• Nail penetration
• Vibration and environment

viii.) Consider the battery pack ages after a period and cannot be used anymore, state the recycling process.

Answer -

• Use battery for low current applications.
• Dismantle battery anode and cathodes send back to manufacturer to re-cycling

ix.) State the reasons of thermal runaway and how can it be prevented.

• Answer -Due to over current during charging or discharging also due to ambient temperature thermal runaway of battery may happened. to protect that we must design a suitable thermal management system it could be active or passive depends upon operating conditions of battery pack .