EMI Control for a Multi-cell Battery

Electromagnetic emissions from multi-cell batteries were previously observed to cause electromagnetic interference (EMI) that can cause nearby electronic safety and health devices to malfunction. While shielding and filtering are the two most common EMI mitigation methods, both have pros and cons and are not applicable in all situations. In this paper, we propose an innovative approach for mitigating EMI emissions from a multicell battery. The new approach takes advantage of the coherent nature of the currents in battery cells, and their structural symmetry found in certain battery packs, and then rearranges them into magnetic mutual cancellation loops so that the magnetic fields produced from the battery cells are cancelling each other. Using an electronic device typically used in underground coal mines as an example, the proposed approach can effectively reduce the EMI from the device by 25dB by simply rearranging the position of the battery cells.