This procedure tests the 12V battery state of charge, capacity, and cranking ability using a digital battery tester to determine if the battery requires charging or replacement.

Warnings

Tools required

Preparation

1. Ensure vehicle has been off for at least 2 hours for accurate state-of-charge reading
2. Park vehicle on level ground with engine off and all accessories turned off
3. Ensure battery tester is calibrated and functioning properly
4. Verify battery type and cold cranking amp (CCA) rating from battery label - typically 550-650 CCA for this vehicle

Procedure

1. 1

   Access battery and inspect condition
   Open hood and locate battery in engine compartment on driver's side. Visually inspect battery case for cracks, bulging, or leakage. Check for corrosion on terminals and cables. Note battery manufacture date on label - batteries older than 4-5 years may need replacement regardless of test results.
2. 2

   Clean battery terminals if necessary
   If corrosion is present on battery terminals or cable ends, disconnect negative terminal first, then positive terminal. Clean both terminals and cable ends with battery terminal brush until bright metal is visible. Reconnect positive first, then negative. Torque battery terminal bolts to specification.
   ⚠Always disconnect negative terminal first and reconnect it last to prevent short circuit
   Torque spec

   Battery Terminal Bolts7 Nm (5 lb-ft)
3. 3

   Perform initial voltage test
   With engine off and all accessories off, connect battery tester or multimeter to battery terminals (positive to positive, negative to negative). Record resting voltage. A fully charged battery should read 12.6-12.8V. Below 12.4V indicates partial discharge; below 12.0V indicates significant discharge requiring charging before load testing.
4. 4

   Enter battery specifications into tester
   Input battery rating information into digital battery tester. Enter CCA rating from battery label (typically 550-650 CCA for 2016-2024 Tucson 2.5L). Select battery type (typically flooded lead-acid or AGM depending on trim level). Input current ambient temperature.
5. 5

   Perform state of charge test
   Follow battery tester prompts to perform state of charge test. Tester will measure voltage and internal resistance to determine charge level. If battery shows less than 75% state of charge, charge battery fully before proceeding to load test. Use appropriate battery charger following manufacturer instructions.
6. 6

   Perform cranking/load test
   With battery at full charge (12.6V or higher), perform load test according to tester instructions. Most testers will apply a load equivalent to half the CCA rating for 15 seconds. Battery voltage should remain above 9.6V during load test at 70°F. Lower voltages indicate weak battery requiring replacement.
   ⚠Battery and cables may become warm during load test - do not touch terminals during or immediately after testing
7. 7

   Perform cranking system test (optional)
   Connect tester clamp around positive battery cable if tester supports cranking analysis. Have assistant crank engine for 5 seconds while tester records voltage drop and current draw. Normal cranking voltage should stay above 9.6V with current draw between 150-250 amps. Excessive current or voltage drop indicates starter or engine mechanical issues.
8. 8

   Perform charging system test (optional)
   Start engine and allow to idle. Measure voltage at battery terminals with engine running. Should read 13.8-14.8V indicating proper alternator function. Rev engine to 2000 RPM and turn on high-load accessories (headlights, rear defroster, HVAC fan). Voltage should remain above 13.5V. Lower voltage indicates charging system issues.
9. 9

   Record and interpret test results
   Document all test results including resting voltage, load test voltage, CCA rating, and measured CCA capacity. Battery should test at 90% or higher of rated CCA when new, 75% or higher for batteries 2-3 years old. Replace battery if testing below 50% of rated capacity or if load test voltage drops below 9.6V.

Reassembly

1. If terminals were disconnected for cleaning, ensure battery terminal bolts are torqued to 7.0 Nm (5.0 lb-ft)
2. Apply battery terminal protector spray to prevent future corrosion
3. Verify radio presets and clock settings were not lost - reprogram if necessary
4. Reset power windows and sunroof initialization if terminals were disconnected by fully opening and closing each window

Verification

• Confirm battery resting voltage reads 12.6V or higher after successful test
• Verify load test showed battery voltage above 9.6V under load
• Check that battery CCA capacity tests at 75% or higher of rated value
• Ensure all electrical systems function normally after testing
• If battery failed testing, recommend replacement with equivalent or higher CCA-rated battery

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