Symptoms
- Device starts strong then noticeably weakens within minutes
- Runtime is much shorter than when new
- Device shuts off completely under any load
Likely causes
- CommonBattery capacity degraded with ageRechargeable batteries lose capacity gradually with each charge cycle.
- CommonBattery not fully chargedRemoving the device from the charger too early leaves less runtime available.
- PossibleMotor working harder due to debris or resistanceA clogged or dirty mechanism makes the motor draw more current and drain faster.
- Less commonCold temperature affecting the batteryBatteries perform worse and drain faster in cold conditions.
What to do
- Charge the device for a full, uninterrupted cycle per the manual's instructions.
- Clean any moving parts, filters, or mechanisms that could be adding resistance.
- Use the device at room temperature rather than in a cold garage or outdoors.
- Time how long a full charge lasts and compare it to the original spec.
- Check for a firmware or battery health reset option if the device has smart features.
- Avoid letting the battery fully drain repeatedly, which can accelerate wear.
- Replace the battery if it's removable and available, or the whole unit if not.
Tools and parts
Replacement batterySearch: “replacement battery for your cordless gadget model”
When to call a pro
If runtime stays short after a full charge and cleaning, and the battery isn't replaceable, the device is likely at the end of its useful life.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.