CHAPTER 51

Ignition off draw (IOD)-

(same as a Battery electrical drain test or parasitic load test) determines if any component or circuit in a vehicle is causing a drain on the battery when everything is off

Battery electrical drain test

-(same as an Ignition off draw (IOD) or parasitic load test) determines if any component or circuit in a vehicle is causing a drain on the battery when everything is off

6. When measuring the specific gravity of the electrolyte, the maximum allowable difference between the highest and lowest hydrometer reading is .

0.050

1. Technician A says that distilled or clean drinking water should be added to a battery when the electrolyte level is low. Technician B says that fresh electrolyte (solution of acid and water) should be added. Which technician is correct?

a. Technician A only

9. Normal battery drain (parasitic drain) in a vehicle with many computer and electronic circuits is .

20 to 30 milliamperes

4. Many vehicle manufacturers recommend that a special electrical connector be installed between the battery and the battery cable when testing for .

A. battery drain (parasitic drain)

5. When load testing a battery, which battery rating is often used to determine how much load to apply to the battery?

CCA

2. What are the steps for performing a battery load test?

Step 1-Determine the CCA rating of the battery. The proper electrical load used to test a battery is half of the CCA rating or three times the ampere-hour rating, with a minimum 150 ampere load. Step 2-Connect the load tester to the battery. Follow the instructions for the tester being used. Step 3-Apply the load for a full 15 seconds. Observe the voltmeter during the load testing and check the voltage at the end of the 15 sec. period while the battery is still under load. A good battery should indicate above 9.6V Step 4-Repeat the test. Many battery manufacturers recommend performing the load test twice, using the first load period to remove the surface charge on the battery and the second test to provide a truer indication of the condition of the battery. Wait 30 seconds between tests to allow time for the battery to recover

3. How is a battery drain test performed?

Step 1-Make certain that all lights, accessories, and ignition are off Step 2-Check all vehicle doors to be certain that the interior courtesy (dome) lights are off Step 3-Disconnect the negative (-) battery cable and install a parasitic load tool Step 4-Start the engine and drive the vehicle about 10 minutes, being sure to turn on all the lights and accessories including the radio Step 5-Turn the engine and all accessories off including the under hood light Step 6-Connect an ammeter across the parasitic load tool switch and wait 20 minutes for all computers and circuits to shut down Step 7-Open the switch on the load tool and read the battery electrical drain on the meter display

7. A battery high-rate discharge (load capacity) test is being performed on a 12 volt battery. Technician A says that a good battery should have a voltage reading of higher than 9.6 volts while under load at the end of the 15 sec. test. Technician B says that the battery should be discharged (loaded) to twice its CCA rating. Which technician is correct?

Technician A only

4. Why should a battery not be fast charged?

To prevent possible overheating damage to the battery

2. All batteries should be in a secure bracket that is bolted to the vehicle to prevent physical damage to the battery.

True

Dynamic voltage-

is the voltage of the power source (battery) with the circuit in operation

new style batteries use _________________ instead of __________________

lead calcium, lead antimony plate grid construction

always disconnect the _____________________ battery cable when working on any electrical component on a vehicle

negative

___________ is the voltage that exists WITHOUT a load being applied

open circuit voltage

Parasitic load test-

same as a Battery electrical drain test or Ignition off draw (IOD) determines if any component or circuit in a vehicle is causing a drain on the battery when everything is off

Three-minute charge test-

used to check if a battery is sulfated

10. When jump starting, .

The last connection should be the engine block of the dead vehicle

8. When charging a lead-acid (flooded-type) battery, .

The initial charging rate should be about 35 amperes for 30 minutes, the battery may not accept a charge for few hours, yet may still be a good (serviceable) battery and the battery temperature should not exceed 125 ○F (hot to the touch)

3. A battery date code sticker indicates D6. What does this mean?

The date it was shipped from the factory was April 2006

Load test-

designed to test the condition of any battery

______________ is the voltage of the power source with circuit in operation

dynamic voltage

batteries contain acid and release gases ____________ and ______________ during normal charging and discharging cycles

hydrogen and oxygen

Hydrometer-

is a tester that measures the specific gravity

Open circuit voltage-

is the voltage (usually of a battery) that exists without a load being applied