A low battery indicating device is disclosed for indicating that a battery has low power. The device includes an indicator having a body movable between a retracted, unactuated position and an extended, actuated position. The indicator is visible when in the actuated position. The device also includes means for biasing the indicator towards the actuated position, and latch means cooperating with a portion of the body of the indicator, when the latch means is in a stop position, to hold the indicator in its unactuated position. The latch means is movable between the stop position and a go position which frees the indicator to move, under operation of the biasing means, to the actuated position. A memory alloy wire is mechanically associated with the latch means so as to leave the latch means in the stop position when the memory alloy wire is in a relaxed state and to move the latch means to the go position when the memory alloy wire is in a contracted state caused by heating of the memory alloy wire. Electrical sensor circuitry is in communication with the memory alloy wire. The electrical sensor circuitry is adapted to detect when the battery means has low power and cause heating of the memory alloy wire to cause it to change to the contracted state and thereby move the latch means to the go position.