This procedure tests the battery's state of charge, cranking voltage, and overall health using a digital battery tester to determine if the battery requires charging or replacement.

Warnings

Tools required

Parts

• Battery terminal anti-corrosion spray × 1 — Use dielectric grease or commercial battery terminal protectant

Preparation

1. Ensure vehicle has been parked for at least 1 hour with ignition off for accurate testing
2. Open hood and locate battery under hood on driver's side of engine bay
3. Ensure all vehicle accessories are OFF (lights, radio, climate control)
4. Verify battery terminals are accessible and not heavily corroded

Procedure

1. 1

   Inspect battery physical condition
   Visually inspect the battery for physical damage, cracks in the case, bulging sides, or leaking electrolyte. Check the battery manufacture date code on the label (typically a sticker showing month/year). Batteries older than 4-5 years are more likely to fail. Check for corrosion on terminals and cables. If heavy corrosion is present, proceed to cleaning step before testing.
2. 2

   Clean battery terminals if necessary
   If corrosion is present on battery terminals, loosen (but do not remove) the battery terminal bolts using a 10mm socket. Use a wire brush or battery terminal cleaner to remove corrosion from both the battery posts and cable terminals. Clean until bare metal is visible. If terminals must be removed for cleaning, remove negative (-) terminal first, then positive (+) terminal.
   ⚠If removing terminals, always disconnect negative terminal first to prevent shorting tools against vehicle ground.
   Torque spec

   Battery Terminal Bolts8 Nm (6 lb-ft)
3. 3

   Reconnect and torque terminals if removed
   If battery terminals were removed for cleaning, reinstall positive (+) terminal first, then negative (-) terminal. Torque battery terminal bolts to specification. Ensure terminals are seated fully onto battery posts before tightening.
   Torque spec

   Battery Terminal Bolts8 Nm (6 lb-ft)
4. 4

   Measure open-circuit voltage
   Connect digital battery tester or multimeter to battery terminals (red probe to positive, black probe to negative). Record the open-circuit voltage. A fully charged 12V battery should read 12.6-12.8 volts. 12.4V indicates 75% charge, 12.2V indicates 50% charge, and below 12.0V indicates a discharged battery that requires charging before load testing.
5. 5

   Enter vehicle battery specifications
   On the digital battery tester, enter the battery specifications. The 2021-2024 F-150 3.5L EcoBoost typically uses a Group 65 battery rated at 750-850 CCA (Cold Cranking Amps). Check the battery label for exact CCA rating and enter this value into the tester. Select 'Flooded' or 'AGM' battery type as indicated on battery label.
   ℹ️Ford may equip vehicle with either flooded or AGM battery depending on equipment level. AGM batteries are common on models with auto start-stop feature.
6. 6

   Perform battery load test
   Initiate the load test on the digital battery tester. The tester will apply a load equivalent to half the CCA rating for 15 seconds while monitoring voltage. Battery voltage should not drop below 9.6 volts during the load test at 70°F (21°C). If voltage drops below this threshold, battery has failed and requires replacement. Record test results.
7. 7

   Perform cranking voltage test
   With tester still connected, have an assistant start the engine while observing the cranking voltage on the tester display. Cranking voltage should remain above 9.6 volts during cranking. If cranking voltage drops below 9.6 volts, battery is weak or discharged. Allow engine to run for this test, then turn off after reading is obtained.
   ⚠Ensure tester leads are securely connected and clear of moving engine components before cranking engine.
8. 8

   Perform charging system test
   With engine running at idle and tester still connected, observe charging voltage. The alternator should produce 13.8-14.8 volts at idle with all accessories off. Turn on headlights and climate control blower to high; voltage should remain above 13.5 volts under load. If charging voltage is outside these ranges, alternator or voltage regulator may require service.
9. 9

   Interpret test results and document
   Review all test results: open-circuit voltage, load test voltage drop, cranking voltage, and charging system voltage. If battery passed all tests (load test >9.6V, cranking >9.6V, charging 13.8-14.8V), battery is good. If battery failed load test but charging system is good, battery requires replacement. If battery is marginal (12.2-12.4V resting), recommend recharging and retesting. Document all voltage readings for customer records.
10. 10

    Apply terminal protection
    Disconnect battery tester. Apply battery terminal anti-corrosion spray or dielectric grease to battery terminals and cable connections to prevent future corrosion. Ensure terminals are tight to specification and connections are secure.
    Torque spec

    Battery Terminal Bolts8 Nm (6 lb-ft)

Reassembly

1. Verify battery terminals are torqued to specification and connections are secure
2. Ensure no tools or test equipment are left in engine bay
3. Close hood securely

Verification

• If battery was tested with terminals connected throughout procedure, verify vehicle starts normally with no warning lights related to battery or charging system
• If terminals were disconnected, initialize power windows by fully opening and closing each window, and reset radio presets as needed
• Verify all test results were documented showing battery condition (pass/fail/charge and retest)
• Confirm charging system voltage is within 13.8-14.8V range with engine running

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