Due to their properties such as high energy density, lithium-ion battery packs are more and more widespread for many kinds of applications. Although a classical Battery Management System (BMS) can improve the performance and safety of a battery pack, it cannot deal with issues related to aging and cell faults. This paper presents a fault-response approach for battery packs operating at the cell level. It uses a reconfigurable topology combined with agents, that can increase the resilience of a pack in the face of faults. A co-simulation technique based on Matlab/Simulink and the JADE platform is used to test and validate the proposed approach.