An electrolyte monitoring system is disclosed which has an interface module and a sensor assembly. The sensor assembly is attachable to an exterior wall surface of a battery cell for monitoring a level of an electrolyte within the battery cell. The sensor assembly may include an infrared (IR) sensor and a cradle. The IR sensor may be configured to communicate with the interface module and to detect when the electrolyte level within the battery cell drops below a predetermined level. The cradle is configured to be affixed to the exterior wall surface of the battery cell at a desired elevational position in relation to the electrolyte level in the cell. The cradle enables mounting and removal of the IR sensor from the cradle without an external tool.