Heat generation in a battery occurs during charge and discharge due to enthalpy changes, electrochemical polarization and resistive heating inside the cell.
How can a battery pack be heated?
Then the warm air could be sent to the battery pack by fans to heat the low-temperature batteries. The battery pack can be heated from −15 °C to 0 °C in 21 min. Song et al. experimentally validated the effectiveness of air heating using an external power source.
What is a battery pack?
This battery pack is formed by a sandwich construction, which is divided into multiple subdivisions as the waterproof housing and the battery housing. The battery frame is made of lightweight aluminium, which provides a lot of installation space for the cells and increases the battery capacity .
What is battery heating?
The battery heating process is also included in the battery thermal management system. The best battery heating design must meet two goals: heating the battery in the shortest time possible and maintaining the temperature uniformity of the battery.
Experimental results show that under 90 W heating power, the battery pack can be heated from −40 °C to restore 80% of the room-temperature discharge capacity in 15 min . The placement of the electric heater in a battery pack also has an impact on heating performance due to the geometric effect of cells.
Then, the air is conducted in the battery pack for the thermal management; Active technique: part of the exhausted air is brought to the inlet and mixed with new fluid from the atmosphere. Then, the heat exchanger cools down or heats the fluid to reach the optimal temperature for battery pack management.
What is the maximum temperature difference of a battery pack?
According to the numerical analysis of Xueyanh Shen et al., the maximum temperature and the maximum temperature difference of the battery pack are 36.9 °C and 2.4 °C and are decreased by 3.4 % and 5.8 % than traditional Z-shaped ducts. The optimal angle the analysis finds is equal to 19° .