STC 612A Instruction Manual

INSTRUCTION MANUAL

for

S.T.C. Model 612A

6/12v Dynamic Battery Analyzer

Copyright 2001 Stone Technologies Corporation

Available Accessories

Hard Case STC#3030 $16.95

Moulded Plastic case with foam lining and carrying handle. Room
for tester, leads, manual and a digital voltmeter.

Spare Test Leads STC#A306 $12.95

One pair of Red and Black 4 foot leads with insulated alligator
clips.

For Orders and Technical Help:
Contact Stone Technologies at [phone]. Have your serial # available
when you call.

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CONCEPT AND DESCRIPTION OF OPERATION

The Model 612A is a microcomputer controlled intelligent instrument de­signed to dynamically test 6 and 12 volt sealed, lead acid batteries, with ca­pacities ranging from 2 to 24 amp-hours. While the instrument is connected to
a battery, it is continually measuring the battery terminal voltage and report­ing acceptable voltage ranges for various conditions. The microcomputer also
controls time intervals and current levels during the dynamic load phase of the
test. Throughout the remainder of this manual, all values enclosed in paren­theses () refer to 6 volt mode operational values.
A battery test is accomplished in two phases:

#1. Observe the Static Test Indications

Connect the Model 612A to a battery to start the Pre-Load Static Test
phase. To test the battery charging circuit, leave the charging leads connected
to the battery during the first phase of this test. Once the analyzer has dis­played the status of the charging circuit, a charge lead should be removed to
continue testing the battery alone.
The analyzer draws its standby operating current, approximately 24 ma. (23
ma. ), from the battery under test. If the battery does not have sufficient power
to operate the tester, it is definitely not serviceable! During this phase of the
test one of the green leds on the “OK TO TEST” bar will light indicating
whether the analyzer is running in 6 or 12 volt mode. One of the four indica­tors beneath the “PRE-LOAD STATIC TESTING” label will also light corre­sponding to one of the following voltage ranges:

CHARGE TOO HIGH/OPEN BATTERY

This indicator lights when the battery charging circuit is delivering a voltage
which will damage the battery, or the battery may have an “open” cell, thereby
not providing a suitable load for the charger. In either case, this must be

addressed before proceeding.

NORMAL CHARGING VOLTAGE

The indicator lights when the battery voltage is within an acceptable range of
voltage for a charged battery while connected to a properly functioning charg­ing circuit. This indicator may remain on for a short period of time after the
charge circuit is disconnected as the battery voltage gradually decays to its
non-charging level. This is the normal display for a battery connected to

the charging circuit.

Yellow

Green

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Some batteries will show normal voltage when checked with a voltmeter, but
will not supply a significant amount of current. These batteries may display a
number of unexpected results when connected to, or tested by, this Analyzer.
Listed here are some of these indications- ALL OF WHICH SHOW THAT
THE BATTERY IS DEFECTIVE!
a. A voltmeter reads voltage in the normal range, but no lights come on
when Analyzer is connected, or one or more lights flash momentarily and
then go out.
b. A voltmeter reads voltage in the normal range, but the red “BAD” light
shows when the Analyzer is connected.
c. The static test shows “NORMAL CHARGED BATTERY”, but all lights
go out completely when dynamic test is initiated.
d. The static test shows “NORMAL CHARGED BATTERY”, but lights
flicker briefly when dynamic load test is initiated, then return to the static test
condition. This indicates that the Analyzer is not performing the dynamic
test, but in reality the battery voltage is dropping so low under load that it
resets the Analyzer to the static test mode.

The time required for any particular battery to charge from “GOOD” to “MAR­GINAL”, and then possibly to “BAD- DO NOT USE”, gives some indication
of the battery’s ability (or inability) to supply energy. If a battery starts the
load test as “GOOD” and switches to “MARGINAL” near the end of the test
(about 45-60 sec.), it is just approaching the end of its useful service life. A
battery that indicates “MARGINAL” immediately upon the start of the load
test is definitely suspect. Remember, this Analyzer uses only 2% of the battery’s
rated capacity during a single test. A fully charged, nearly new battery will
indicate “GOOD” for at least 10 to 20 load cycles.

In situations where it is difficult or impractical to disconnect the battery from
the charging circuit, load testing the battery while it still connected to the
panel should be o.k., except where poor design of the panel or power supply
allows the high load of the dynamic test to overload the charging circuit and
blow a fuse. If a fuse blows during testing, disconnect the battery before test­ing the battery again on this panel and all other panels of identical model.

The 612A contains a high-temperature shut down circuit. When the internal
temperature exceeds 140 deg. F, the Analyzer will reduce the heat producing
current load and extend the test time to still draw the same total load from the
battery. This extended test time can approach 15 minutes at the higher A.H
settings.

During the discharge period, batteries which are beginning to fail due to high
internal resistance, or which have cells which are beginning to go open, will
not be able to maintain a level of voltage sufficient to keep the “GOOD”
indicator on and the “MARGINAL” indicator may light, sometimes immedi­ately upon beginning of the Dynamic Load Test and sometimes after the test
has been in progress for a period of time. As a general rule, the more quickly
this indicator comes on, the poorer the condition of the battery due to high
internal resistance. If this indicator remains flashing throughout the test inter­val, some charge has been retained by the battery, but the battery should not
be left in service due to high internal voltage drop.

Batteries which consistently test “MARGINAL” without dropping to “BAD”
during repeated Dynamic Load Tests may be serviceable in some light load
applications. The continued use of a battery which tests “MARGINAL” is
definitely not recommended. The “MARGINAL” indication is a sign of an
impending failure.

****The “BAD” indicator will flash during the discharge period if the battery
voltage is less than 11.1 volts (5.5). After this indicator has flashed for 5
seconds, the analyzer will stop discharging the battery and begin flashing this
indicator rapidly to show that the battery is not serviceable. Replace the bat­tery.

This indicator generally comes on if the battery is unable to accept or hold a
charge, or if it has open cells, or a very high internal resistance. Under no

circumstances should a battery be returned to service which is thought to
be charged and tests “BAD”.

SIGNIFICANT INSIGHTS

USE ONLY THE SUPPLIED TEST LEADS. The voltage drop across the

test leads is calibrated and is part of the parameters used to perform the test.
Do not use any other test leads!

Batteries with ratings larger than 12 Amp Hours can be checked by se­quentially performing 2 or more load tests by using additive testing where
the total of the tests equals or slightly exceeds the battery’s rating. For

example, to check a 24 Amp Hour battery, perform two 12 A/H tests. If the
Analyzer becomes too warm to hold during the testing, wait a few minutes
between tests to allow the unit to cool. If you can still hold it, it is OK to
proceed.

-9-

-2-

NORMAL CHARGED BATTERY

NO CHARGING/TOO LOW TO USE

This indicator lights when the battery voltage is within the acceptable range
for a charged battery, disconnected from the charger, and supplying a small
load. If this indicator is on while the charging circuit is connected, it may be
an indication that the charging circuit cannot supply sufficient voltage to fully
charge the battery. This is the normal indication for just the battery con-

nected to the Model 612A.

This indicator lights when the battery voltage is less than acceptable signify­ing that the battery is not charged or could not hold or accept a charge. If the
charging circuit is connected to the battery while giving this indication, then
that circuit may not be functioning or the battery may have one or more shorted
cells. This indicates a significant problem that must be addressed.

The specific meaning of each of these indications is further explained under
General Comments in the “Results and Interpretations” section.

#2 Perform Dyanamic Load Test

After observing the indications during the Pre-Load Static Test phase,
the technician may initiate the Dynamic Load Test phase by depressing one
of the blue keys located below the “BATTERY SIZE A/H” label. Depressing
one of these keys causes the Model 612A to draw a significent load current
depending on the battery’s ampere-hour rating for a time interval calculated
to drain a percentage of the battery’s storage capacity. The specific discharge
rate and time are determined by the microcomputer, based on the ampere­hour rating. Choose a value equal to the battery’s amp-hour rating (round

up to the next value as needed).

During this phase of the test, the green “OK TO TEST” light will go out
and one of the bottom three indicators beneath the “TEST RESULT - DY­NAMIC LOAD” label will begin to flash displaying the voltage range of the
battery while under load. When the specified test interval ends, the indicator
corresponding to the analyzers’s final determination of battery condition will
flash rapidly. The voltage ranges for these indicators are as follows:

Green

Red