I had to think about this one a bit. Please accept this in the fun intended.
Now, since EveryReady spends millions of dollars saying that their batteries
last and last, the question arises as to when they quit. I propose you find 2 of
the little bunnies beating the drum and place one in each and turn them loose.
The one to slow down first would be the weaker battery.
You could try one in a portable cassette player and see if one does not have
enough power to run that player well.
In the event you don't have any bunnies minus batteries or tape players lying
around, you could try the ol' elementary school head jerk test. This process is
entirely unscientific and unprofessionally recognized, and successfully tested
almost every male at least once.
Take a battery in each hand. Extend your unofficial internal battery tester as
far as possible. Then place a battery against each side of the tester
simultaneously. Which ever direction the head jerks farthest, the opposite hand
is holding the stronger battery.
For the layman: stick one battery on each side of the tongue and see which
direction you jump farther. The battery in the opposing hand "may" be stronger.
If none of these options work, you could always go buy 2 new batteries.
Since you didn't state the purpose of needing the battery and to keep this
relevant to ham radio: When the better battery is determined, you can then
in the radio as a reliable memory backup power source.
>>> "Jim and Kate Belt" <email@example.com> 04/15/98 I
have two 9 volt batteries. Energizers. One is new and fresh. The other is
old. Both register 9 volts on the VOM. No exterior markings. How do I
determine that one is fresh and the other not?
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