Abstract: A modification to existing mono-block battery design for positively indicating the operating condition of the battery by adding a failure detector. The voltage of two groups of internal series connected cells are measured and compared. An indicator of one color indicates the battery is operating normally and an indicator of a contrasting color indicates the battery is defective. The indicator may be located remotely from the failure detector. An additional embodiment provides for an optical indicator located remotely from the failure detector such that luminous energy is transferred from the failure detector to the remote indicator by an optical-conductor.

Abstract: A modification to existing mono-block battery design for positively indicating the operating condition of the battery. The voltage of two groups of internal series connected cells are measured and compared. An indicator of one color indicates the battery is operating normally, an indicator of a contrasting color indicates the battery is defective.