Modular Design of Lithium-ion Battery Packs for Cylindrical Battery Cabins of AUV

For autonomous undersea vehicles(AUV), the capacity and reliability of battery packs depend on their range, safety, and overall performance. According to the technical specifications of the energy system of an AUV, the 21700 lithium-ion battery was selected as the unit cell for the battery pack design with the idea of a modular and double-redundant design. A single module can completely use the inner space of the cylindrical battery cabin to improve the capacity of the battery packs, while the structure of multiple modules in series and parallel is convenient for locating faults and carrying out maintenance. Two parallel battery packs can result improved reliability. The test results show that the energy density of the system can reach to 200 Wh/kg and battery packs in modular design have higher energy density, reliability, and maintainability.