Abstract: The present disclosure is directed, in certain embodiments, to a flow cell battery system. A battery management system detects that a first power module and a second power module located adjacent to the first power module are operating at different states of charge. After determining that the second power module is at the lower state of charge than the first power module, a negative-side switch associated with the second power module is adjusted to an open position, thereby preventing flow of electrical current from a negative terminal of the second power module to electrical ground.