Laptop Battery Pack: battery cell imbalance. One cell group reaches its voltage limit before the others.

The distinguishing clue

The percentage jumps, charging stops early or shutdown occurs with charge still reported.

Checks before an assessment

If the case is flat and the pack is not unusually hot, record the reported charge and runtime. Leave any swollen or damaged device off and unplugged.

Stop point: A swollen, leaking or unusually hot lithium battery must not be charged or compressed.

Workshop confirmation and repair

Device-level check: Read capacity and cycle information, compare voltage behaviour under load and inspect for swelling or heat.

Targeted check: Compare pack data and voltage behaviour across a controlled charge and discharge. If confirmed: Replace the imbalanced pack after confirming the charger is stable.

Repair boundary: Replace a confirmed worn or unsafe battery with the exact compatible pack and verify charge control.

Related cause to rule out

When runtime falls steadily and the laptop may shut down when demand increases, also consider Laptop Battery Pack: worn battery cells before choosing a repair.

Checks after the work

After repair or replacement, check charging to full, controlled discharge, sleep and several charger transitions.

For an AEPC repair assessment in East Auckland, provide the exact model and observed clue. Call 027 908 8880 before visiting the Burswood workshop.