Unknown Carbon Hearing Aid Battery (5)
This unnamed carbon-zinc 3-volt hearing aid battery was used in
carbon hearing aids around 1921.
Although it is unnamed, it is identical to the
Globe No. 5 carbon-zinc battery, and is
of a similar vintage.
This battery measured 3 9/16" x 2 3/16" x 1⅛" (9.1 x 5.5 x 2.9 cm).
It weighed 6˝ oz (184 g).
The pin spacing was exactly 1" (2.5 cm). Note that the pins are
of uneven diameter. The right pin is thicker
(⅛") than the left pin (3/32") in order to preserve correct polarity.
Having the right pin thicker than the left pin was very unusual.
Almost all other batteries were the reverse with the larger pin on the