Mallory Duracell Model BT-22 Hearing Aid Battery Tester
The Mallory Duracell Model BT-22 hearing aid battery tester was made by/for
the Mallory Battery Company of Tarrytown, NY around 1975.
This meter measured 4" x 2" x 2" (10.2 x 7.3 x
5.3 cm) and weighed 7.0 oz. (198 g).
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Front view of the Mallory Duracell Model BT-22 hearing aid battery
tester. You
could use the red and black probes for testing the battery, or lay the
meter down and place the positive terminal of the battery on the metal
plate (bottom center) and then just use the black probe for the
negative terminal.
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Close-up of the meter of the Mallory Duracell Model BT-22 hearing aid
battery tester. The meter had a single scale although the meter could
measure three different voltage ranges. Reading the meter was
easy. If the needle remained in the red, the battery was bad and needed
to be replaced, if it was in the green, it was good, and if it was in
the yellow area between them, it was warning you the battery would soon
need to be replaced. |
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Close-up of the bottom front of the Mallory Duracell Model BT-22 hearing
aid battery tester showing the three-position switch. In the left
position it measured single cells—namely silver and carbon-zinc 1½ volt
batteries and mercury 1.35 volt batteries.
In the center position it could measure 2 cells (in series) with a
combined voltage of 2.7 to 3.0 volts.
In the right position it could measure 3 cells (in series) with a
combined voltage of 4.05 to 4½ volts. |
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View of the back of the Mallory Duracell Model BT-22 hearing aid
battery tester showing the instructions and manufacturer's information.
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