Improving Battery Design for Electromagnetic Compatibility: A Magnetic Field Cancellation Method

With the increasing demand of power and energy, more and more cells are packed into battery modules. Consequently, the electromagnetic (EM) emissions from batteries also intensify. These emissions have been observed to interfere with nearby electronic safety and health devices, causing malfunctions. While conventional methods, such as shielding, filtering, and distance separation, are commonly used to mitigate the interference issue, each has its own limitations and may not be applicable in all situations. On the other hand, magnetic field cancellation methods found in certain applications offer distinct advantages in addressing challenging magnetic field shielding or compensation issues. In this article, we introduce a novel approach to mitigate EM emissions from batteries consisting of common cylindrical form cells. The new approach leverages the coherent nature of battery cell currents when powering external load and the paired structure present in the battery pack, and then rearranges the cells so that the magnetic fields of the loops of paired cells are canceling one another. We demonstrate the validity of our approach in addressing the EM interference issue that exists in an electronic device currently used in underground coal mines. The results show a significant reduction in EM emission from the battery, highlighting the effectiveness of our approach in real applications.