BATTERY UNITS

摘要

An emergency alarm is embodied in the rechargeable battery pack (5) for a portable telephone handset. The battery pack (5) includes a housing (6) of which a part (7) houses the rechargeable cells. Contacts (9) enable the cells to power the handset when the pack (5) is latched into position on the handset by latches (10, 12, 14). Within the housing (6), alarm circuitry is incorporated which includes an alarm unit connectable to be energised by the cells (7) upon operation of a push button switch (18). The alarm unit may emit an audible and/or a visual alarm signal. In the case where the alarm signal is an audible one, apertures (20) for emission of the sound may be provided. In use, the user may carry the battery pack in their car or handbag as a spare for their telephone handset. In the event of an attack or threat of an attack, they can activate the alarm by means of the push button (18).