Battery testing from start to finish
Customer says: “It just clicks in the morning.” Is the battery actually bad, or are we about to replace the wrong part?
What this lesson covers
CORE TEACHING 12 V lead-acid battery basics; six cells; resting voltage; state of charge vs battery health; terminals; surface charge; load; cranking voltage; CCA; why 12.6 V alone does not prove a good battery. PRACTICAL DEMONSTRATIONS AND TESTS Measure resting voltage; inspect terminals; apply load/tester; crank engine while watching voltage; compare battery-post voltage with clamp voltage; show a healthy vs weak result. ADVANCED / SCAN TOOL LAYER Show scan-tool battery voltage if available and compare it with the meter. Briefly introduce current clamp during cranking. KEY DIAGNOSTIC QUESTIONS Is it charged? Can it carry load? Does voltage collapse only when cranking? Are the posts and clamps giving the same reading? MUST-COVER CHECKPOINTS 1) Visual/terminal check 2) resting voltage 3) state-of-charge caveat 4) load/CCA test 5) cranking voltage 6) post-vs-clamp check 7) final verdict
What you will be able to do
Customer says: “It just clicks in the morning.” Is the battery actually bad, or are we about to replace the wrong part?
Where it sits in the programme
- Builds on
- The learner’s existing workshop experience; no earlier Voltzs lesson is required.
- Feeds into
- Lesson 2: Voltage on a real vehicle