Testing Batteries, Starters and Charging systems using the D-TAC

What is a D-TAC machine The D-TAC machine is a combination of a hand held battery tester and a battery charger The tester and charger are electronically linked. This allows the tester to analyze current flow during charging which helps determine the true battery condition

Conductance testing The D-TAC is a ‘conductance’ type battery tester The tester sends a small A/C current through the battery The difference between the A/C signal applied to the battery and that same signal exiting the battery is directly related to the ability of the battery plates to produce electric current Signal sent into the battery Signal coming out of the battery

Load testing vs. conductance testing A load test places a very high current load on a battery which puts the battery under extreme stress and can cause damage to the battery The D-TAC tester is able to test the battery condition using low current, which puts less strain on the battery and allows the tester to be lightweight and easily portable Load testing machine [VAT]

Load testing machines A load testing machine [VAT] draws several hundred amps from the battery while the technician monitors the voltage level between the terminals. Normally a load test is run for 15 seconds

D-TAC / charger interface LEDs indicate charger status The D-TAC can also interface with a battery charger. This provides the D-TAC with data on the rate at which the battery plates can recharge. When the D-TAC is used with the battery charger a much more accurate picture of battery condition is available.

Digital testing The D-TAC uses digital technology to analyze the condition of the battery. It may perform several different types of test in a fraction of a second.

D-TAC can test a partially charged battery A dead or partially charged battery must be fast charged for 15 to 20 minutes before load testing with a VAT The D-TAC can test partially charged batteries This saves you the wasted time setting up a battery charger only to find out that the battery is no good.

Basic battery test using the D-TACT The basic battery test can be done with or without the D-TAC being connected to the charger unit. Connect the low current battery clamps to the battery terminals.

Socket for adapter cables D-TAC controls Low current battery test cable Socket for adapter cables Printer Display screen Activity LED array Menu control buttons Select button On / Off button Infrared temperature sensor

Select battery test from the menu Measured voltage at battery clamps D-TAC internal AA batteries SOC Scroll up or down the main menu to find the battery test Press the ‘S’ select button to proceed

Diagnostic charge testing If the SOC of the battery is low it is best to select “Diagnostic Charge’ from the main menu This will require connecting the hand held D-TAC unit to the charging unit. Since you need to charge the battery anyway why not do an advanced battery test that will insure the battery can be returned to service

Identify the test vehicle - optional If you plan to save the data from the test you will need to enter the repair order number , customer name or vehicle make and year

Is battery in or out of vehicle There may be more line ‘noise’ if the battery is connected to the vehicles electrical system

Top post or side post There is generally less resistance between the battery clamps and the terminals on a side post battery

Application Marine Lawn and garden Group 31 Commercial 4D/8D Marine batteries may be deep cycle type batteries that have slightly different conductance properties Lawn and garden Usually deep cycle Group 31 One of the largest automotive batteries group size – often deep cycle Commercial 4D/8D Very large battery used in golf carts and marine applications – deep cycle type

Battery type AGM [Absorbed Glass Mat] batteries have slightly different conductance properties from conventional liquid electrolyte type batteries Spiral wound batteries have a larger plate area than flat plate batteries

AGM battery for hybrids AGM batteries are found in Toyota hybrids and motorcycles AGM battery for hybrids Positive terminal has a plastic cover The function of the 12 volt battery in Toyota hybrids is to provide current for the computer systems, lighting system and accessories It does not provide current to start the engine when the ignition is off

Battery type AGM Spiral are aftermarket batteries that look like a 6 pack of soda cans wrapped in shrink wrap

Other European countries Ratting units Japan Germany Other European countries The D-TAC can use other types of battery ratings but the CCA rating is the most common type found on batteries sold in the USA

CCA Rating The CCA rating is usually found on the battery information placard on the top of the battery

Enter the CCA rating Use the up and down arrows to change the CCA rating

Measure battery temperature The temperature of the battery has a major effect on it’s conductance Battery temperature must be entered to achieve accurate test results

Measure battery temperature Hold the D-TAC in a vertical position directly over the battery case Bring the D-TAC to about 2 inches above the battery and press the right arrow button to record the temperature

Battery test results The battery test takes just a few seconds If the battery passes the test the test result can be printed out or saved to a PC

Printout The internal printer uses thermal printing paper – no ink is required

Battery needs to be recharged This battery was essentially dead. The test indicates that the battery is safe to be recharged The battery should be recharged in diagnostic mode using the D-TAC and D-TAC charger

Recharging required In some cases the low SOC of the battery will require recharging before diagnosis can be completed

Warning message If the D-TAC is detached from the charging unit you will receive this warning message

Mount the D-TAC to the charger unit The D-TAC unit must be mounted to the charging unit.

Connect the high current battery clamps The charger unit has a set of high current battery clamps that need to be connected to the battery for advances diagnostic testing The D-TAC low current clamps are not needed during the charging test Low current clamps High current clamps

Charger on / off switch The charger unit has an on/off switch located on the rear panel of the charger When the charger is plugged in and the switch is turned on the bottom green LED on top of the charger unit will be illuminated

Connect charger clamps to the battery Low current clamps do not need to be connected The high current battery clamps should be attached to battery terminal The D-TAC will measure battery voltage through the charger clamps during diagnostic mode charging

Out of car charging Charging can be done with the battery in or out of the car. The low current battery clamps do not need to be connected to the battery

Remove cell covers The cell covers should be removed during charging Any hydrogen gas that is generated during charging must be allowed to dissipate

Charger unit LEDs There are four LEDs on the top of the charger unit: Power Charging Fault Communication The ‘Fault’ led illuminates if a shorted battery cell is detected The ‘Comm’ light flashes when data is being transferred between the D-TAC and charger unit

Select ‘Diagnostic Charge’ from the menu If your starting from scratch you will need to select the diagnostic test from the main menu

Select Diagnostic charging test Select ‘diagnostic charge’ Follow the menu prompts to identify the vehicle and battery parameters

Diagnostic charging Number of charging hours multiplied by charging current Estimated time to complete charge During diagnostic charging the charging voltage is varied by the D-TAC while the charging current is monitored Initial charging may be done at a relative high voltage level to see how easily the battery accepts a charge

Diagnostic charging As charging continues the charging voltage will be reduced with a corresponding reduction of charging current If an AGM type battery was specified the charging voltage would be limited to 14.4 volts

Battery fault detected ‘Fault’ indicator If a shorted cell is detected the charging test will abort and the fault indicator LED will illuminate

Battery failed charging diagnostic test A heavily sulfated battery will not accept a charge The D-TAC measures how many amps pass through the battery at different charging voltage and the increase in voltage after charging for a short time. If the rates are too low the test will return a failure message

Diagnostic charge test report The report shows the SOC voltage and measured CCA after the recharge process was completed. Additional information on charge time and the number of amp/hours accepted

Battery, Starting and Charging system test The ‘Complete System Test’ exams the battery, starting system and charging system in one test.

For this series of tests you will need to connect the inductive ‘Amp’ clamp to the accessory socket on the left side of the D-TAC Inductive Amp clamp AMP clamp

Inductive clamp orientation arrow The arrow on the inductive clamp normally faces in the direction of current flow The inductive clamps measures the strength of the magnetic field surrounding a conductor It is important that the clamp jaws are in firm contact with each other

Setup for system test The inductive clamps is installed surrounding the battery negative cable The D-TAC will measure the current flowing between battery and starter motor during the cranking test and between the battery and alternator during the charging system test Inductive amp clamp

System test – main menu Begin the system test by scrolling down using the arrow buttons

Zero inductive clamp before installing Do not connect the amps clamp to the ground cable before the D-TAC completes calibration [zeroing] Also, make sure the amp clamp is completely closed – so the ends of the clamp are in firm contact As soon as you begin the system test the zeroing procedure will run

Install inductive clamp After this screen is displayed you can install the inductive clamp around the ground cable The clamp should surround the cable and the ends should snap tightly together

Inductive clamp installed on neg cable The low current battery clamps are installed on the battery terminals The inductive clamp is installed around the ground cable

Inductive clamp orientation The arrow on the inductive clamp normally points in the direction of current flow Since the test will measure charging and starting current it doesn't make any difference which way the arrow faces

Enter battery specifications Identifying the vehicle and entering battery parameters is done the same ways as for basic battery testing

Jump start post One difference in the battery parameters is that for the system test they add a selection for a ‘jump start’ post

On some vehicles the battery is located in the trunk or under the rear seat. To facilitate jump starting a terminal is located under the hood – usually next to the fuse box – that connects directly to the battery positive post The negative cable is connected to a good engine ground Jump start post

Negative cable Note: Battery charger cables – not D-TAC cables Any clean, unpainted surface on the engine block, cylinder head or transmission can be used to connect the D-TAC to battery negative.

Battery test After inputting the basic battery parameters a regular battery test will run If battery SOC is low the D-TAC will request a diagnostic charge test After the battery test the starting system test

Starting system test After the battery test the starting system test is run Unlike starter testing using a VAT the D-TAC does not require that the ignition of fuel system be disabled

Results of Starter test The D-DAC can measure the amount of current drawn by the starter in a few milliseconds The test here took less than one second

Starter current graph The starter draw can also be displayed as a graph The graph here shows the voltage level while the engine was cranked by the starter

Charging system test The charging system is tested next

Baseline voltage and current The D-TAC starts by measuring charging voltage and current at idle with no loads turned on

Increase engine speed to about 1500 rpm Once the D-TAC reads the voltage and current it wants to see what happens when the rpm is near cruise speed rpm

Open the throttle If the throttle is mechanically controlled you can increase the engine rpm by manually operating the throttle linkage If the throttle is electronically controlled you will need to operate the gas pedal from inside the car

Testing at idle with loads turned on Now the D-TAC wants to see how much current the alternator can produce at idle with about 30 amps of loads turned on

Increase engine speed again Rev the engine to about 1500 rpm for a second time to allow the D-TAC to record alternator voltage and current output at cruise speed with accessory loads turned on

Return engine to idle The D-TAC does a final measurement of voltage and current at idle before test is finished

Final analysis Once all the system measurements are made the D-TAC records all the data for uploading and printing

Turn off engine The engine can now be shut down while the D-TAC finalizes the data

Printout The printout shows the data for all three test

Ripple current Ripple is the small amount of AC current produced by the alternator that doesn’t get converted to DC The D-TAC uses this current to determine engine rpm increase/decrease Excess ripple current indicates a defective diode or stator winding in the alternator

Advanced D-TAC tests See the ‘Advanced D-TAC testing’ presentation for information on: Voltage drop testing Multimeter functions Inductive ammeter functions Lab Scope functions Temperature probe [contact and immersion] temperature measurement Infrared temperature measurement