A battery system has a battery cell including a can and tabs, flexible circuits on and electrically isolated from the can, and electrically connected with the tabs, and a monolithic integrated circuit. The monolithic integrated circuit is mounted to the can via thermally conductive adhesive such that the can and monolithic integrated circuit are electrically isolated from one another. The monolithic integrated circuit is also wire bonded to the flexible circuits, and configured to measure and transmit data about the battery cell.