Vacuum runs for only a few minutes on a full charge before shutting off.

Safety first: Remove the battery before inspection.

• Confirm full charge: Charge the battery until the charger indicates full. Then immediately test runtime in normal mode on a hard floor.
• Compare to specification: Check the user manual for expected runtime. If actual runtime is less than half of specified, the battery is likely worn.
• Test another battery: If available, compare runtimes between batteries.

Short runtime with a fully charged battery almost always indicates battery wear. Replace the battery pack with a genuine Hitachi unit.