Symptoms
- Runtime is much shorter than when new
- Battery indicator drops quickly under load
- Vacuum shuts off suddenly mid-clean
- Battery won't hold a full charge overnight
Likely causes
- CommonBattery capacity degraded with ageRechargeable batteries lose capacity after hundreds of charge cycles, which is normal wear.
- CommonClogs forcing the motor to work harderA blocked filter or brush roll makes the motor draw more power, draining the battery faster.
- PossibleUsing max or boost mode most of the timeHigh-power modes drain the battery much faster than eco or standard settings.
- PossibleDirty battery contactsGrime on the contacts between battery and vacuum can cause poor connection and inconsistent power.
- Less commonCharging dock or cable faultA failing charger may not fully charge the battery even when it appears connected.
What to do
- Clean or replace the filter and check for clogs in the brush roll and hose.
- Wipe the battery and charger contacts with a dry cloth.
- Charge the vacuum fully and let it charge undisturbed for the full recommended time.
- Note the runtime on a standard suction setting rather than boost or max mode.
- Check the battery age against the manufacturer's typical lifespan, often 2–4 years.
- If runtime is still short after cleaning and a full charge, the battery likely needs replacing.
- Order a manufacturer-compatible replacement battery if the vacuum otherwise works well.
Tools and parts
- Dry cloth
Cordless vacuum replacement batterySearch: “cordless vacuum battery replacement”
When to call a pro
If a new battery doesn't restore runtime, or the battery feels hot or swollen, stop using it and contact the manufacturer for service.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.