Triplett Chek-A-Cell – PN: 3276 - Manual (Page 5)

If testing a 6 Volt sealed lead acid battery, and the reading drops
below 6.20 Volts in several seconds, the battery is “weak” and
may need to be replaced (or the charging circuitry may have a
fault).
If testing a 12 Volt sealed lead acid battery, and the reading drops
below 12.40 Volts in several seconds, the battery is “weak” and
may need to be replaced (or the charging circuitry may have a
fault).
If a 6 Volt sealed lead acid battery displays a voltage in excess of
6.8 volts, it has a surface charge. If the voltage does not drop to
6.3 volts in one or two seconds, the battery must be allowed to set
for several hours for the surface charge to dissipate.
If a 12 Volt sealed lead acid battery displays a voltage in excess
of 13.6 volts, it has a surface charge. If the voltage does not drop
to 12.6 volts in one or two seconds, the battery must be allowed
to set for several hours for the surface charge to dissipate.
Rechargeable batteries can develop internal shorts that discharge
the battery. If the battery is charged using a trickle charger (usu-
ally takes 12 to 16 hours to charge), the internal shorts often
prevent the battery from obtaining a full charge. When tested with
the CHEK-A-CELL, the battery’s voltage will be low, and it will
drop quickly, indicating that the battery is bad.
However, a battery with an internal short can sometimes be fully
charged if a rapid charger is used (charges the battery in an
hour or less). The high charge rate can overpower the short and
charge the battery. If such a battery is tested with the CHEK-A-
CELL right after being charged, the battery may appear to be
OK. However, if the battery is allowed to set for a few hours, the
internal short will drain the charge from the battery. Testing with
the CHEK-A-CELL at this time will show the battery is bad.
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