Abstract: A battery-cell protection system includes a processor, a wake-up circuit, and a shunt or isolation switch. The processor responds to voltages from cells in a battery by detecting any of the voltages being less than or equal to a predetermined threshold voltage. The processor samples cell voltages at a fast sampling rate and compares the sampled voltages to a predetermined threshold value. The processor further identifies any cell having an associated voltage that is less than or equal to the predetermined threshold voltage. The wake-up circuit responds to a current load from the battery by activating the processor. The shunt switch responds to the identification of the cell by selectively electrically shunting the identified cell to allow the other cells of the battery to continue to supply power to a connected load. The monitoring and identification of cells are performed in parallel to rapidly monitor all of the cells at once.

Abstract: A self-contained maintenance-free emergency lighting system involving a housing including a tough plastic cover so as to protect the system from vandalism; in order to test the system to determine whether it is operating properly, i.e., such that the emergency battery supply will furnish power to the emergency lamp, a magnetically operated test switch is included within the housing. By such feature, no external projection of a switch or the like is required. An arrangement is also provided for allowing the emergency lamp or bulb to float; that is to say, to preclude any kind of shock to the dome or cover from causing breakage of such lamp. Also, the plastic dome is extremely difficult to remove in that a tamper-proof screw is provided which is not readily visible nor is it readily accessible. An electrical circuit arrangement is also provided which includes a transfer relay which is normally open.