Cordless vacuum runs but battery indicator LEDs behave erratically (jumping from full to empty)

Safety first: Remove the battery before inspection.

Steps:

• Perform a full cycle: Fully charge the battery, then run the vacuum on normal mode until it stops. Recharge fully again. This can help recalibrate the fuel gauge.
• Check indicator contacts: If the LEDs are on the battery, inspect the housing and contacts for damage or looseness.
• Monitor run time: If actual run time is normal despite odd LED behavior, the issue is likely just the indicator.

If run time is also poor, replace the battery. If LEDs are on the main body and misread with multiple batteries, the indicator PCB may need service.