Triplett 3221 - Manual (Page 2)

Using the following chart, the “open circuit voltage” measured by
the BQ can be related to the battery’s “percentage of charge”.
6 VOLT 12 VOLT APPROX.
BATTERY BATTERY % OF CHARGE
6.00 volts 12.00 volts 25%
6.10 volts 12.20 volts 50%
6.22 volts 12.45 volts 75%
6.32 volts 12.65 volts 100%
This table is based on a battery electrolyte temperature of 77° F. Significantly
higher or lower temperatures will affect the validity of the presented values.
NOTE:
A recently charged battery, or a battery that has been charged in service (such
as when charged by a vehicle charging system) will exhibit a “surface charge”.
Before accurate readings with the BQ can be obtained, the surface charge must
be allowed to dissipate, or a load must be placed on the battery to “bleed” the
charge off. The surface charge can be dissipated by allowing a recently charged
battery to stand for at least 12 hours. Alternately, if installed in a vehicle, the
headlights can be turned on for several minutes to bleed the charge off.
VEHICLE ELECTRICAL SYSTEM TESTING:
With the vehicle off, connect the BQ to the posts of the battery and note the
battery voltage reading. For a charged battery in a 12 volt system, the reading
should be at least 12 volts.
Crank the engine to start the vehicle. The battery voltage should remain above
10 volts during cranking.
When the vehicle starts running, the charging current delivered to the battery
should cause the voltage to rise. The actual voltage depends on the initial state
of charge of the battery, the ambient temperature, and the performance of the
vehicle’s charging system. At low temperatures, the charging voltage is allowed
to be higher than at moderate temperatures. Specifications for the actual al-
lowed voltages can be found in the vehicle and battery manufacturer’s specifi-
cations. In any case, it would be very unusual for the battery voltage, during
charging, to exceed 16 volts in any normal situation. If the battery voltage does
exceed 16 volts, the battery, the charging system, and the specifications, must
be closely examined to determine if a malfunction exists.
A common problem in many vehicles is corrosion that develops on the surface
of the battery posts (caused by outgassing from the battery electrolyte). This
corrosion does not conduct electricity, and so, interferes with the current flow
from the battery posts to the post clamps and battery cables. The corrosion is
not always visible on the outside surface of the clamps, often developing where
it cannot be seen, between the battery posts and clamps.
Another cause for poor electrical connection is that the clamps require replace-
ment. Over a period of time, the soft lead of the clamps and the battery posts
may deform. Also, repeated cleaning of the posts and clamps with a cleaning
tool tends to “ream out” the clamps and reduces the diameter of the posts,
making it difficult to get the clamps to tighten down properly. When these
things happen, tightening the bolts on the clamps won’t always allow the clamps
to get a good “grip” on the battery posts.
Problems with the clamps can be tested for by moving the connections of the
BQ from the battery posts to the clamps. If the BQ’s reading changes by more
than .05 volts, then a problem exists.
The general technique of measuring the voltage on different sides of an electri-
cal connection can be used to identify connections where “resistance” is caus-
ing a “voltage drop”. Any connection that causes a loss of more than .05 volts
should be suspect.
SPECIFICATIONS:
OPERATING VOLTAGE .................... 5.75 Volts to 19.99 Volts
RESOLUTION .................................. 0.01 volts
ACCURACY ..................................... ±0.03 volts (at 25° C, ± 5°)
LOAD CURRENT ............................. typically between 75 & 200mA
MAXIMUM DURATION OF
MEASUREMENT .............................. 5 minutes @ 12 Volts
MAXIMUM INPUT VOLTAGE .......... 240 VDC, 240 VRMS SINE
OVERVOLTAGE WARNING BEEPER ... typically activates between 30V & 40V
MAXIMUM DURATION
OF OVERVOLTAGE ..................... 30 seconds for voltages less
than the maximum input
DISPLAY .......................................... 3 1/2 digit, .43” high red LEDs
DIMENSIONS .................................. approx. 3 3/8” x 3 5/8” x 7/8”
Negative Terminal ...................... approx. 7/8” long
Positive Test Lead ...................... approx. 18” long
WEIGHT (incl. terminal and lead) .... 4.9 oz.
Triplett Corporation One Triplett Drive Bluffton, OH 45817
800-TRIPLETT FAX: 419-358-7956 www.triplett.com
TRIPLETT
PN 84-762