One obvious and dramatic change in batteries is size. The Columbia Dry Cell was 6 inches long; modern batteries for hearing aids and watches are smaller than 1/4 inch by 1/8 inch. The American ...

we chose an L925-size battery because it's a direct replacement for the Odyssey PC-925 dry-cell ($180) we'd been using. The Odyssey is a favorite among racers because it's small, can be mounted in ...