Abstract: A thermal fuse for use in interconnection of lead acid batteries which will fuse as a result of heat being conducted through the fuse from the batteries or other devices to which it is attached, rather than as a result of direct heating of the fuse consequent on the current carried by the fuse. The fuse has a pair of mounting plates connected to terminals of the fuse with a heat meltable electric current conducting material in solid form disposed between the plates to provide a flow path for electric current. A member is also disposed between the plates connecting with the solidified heat meltable material and of sufficient mass so that when the material melts, the member draws substantially all of the material with it as it falls due to gravity from between the mounting plates.

Abstract: A battery charging system is disclosed wherein there is control means connected with a battery charger responsive to the temperature of a temperature sensor connected with a battery to sense its temperature whereby to switch off the charging when the battery temperature is at or above a predetermined temperature unsuitable for charging. The control means includes a signal transmitter and a signal receiver. The signal transmitter applies a pulsed signal to the charging leads when the temperature of the battery is at or above the predetermined temperature and the receiver detects this and switches off the charging. A signal transmitter and temperature sensor, and a battery fitted therewith is also disclosed.