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A sharp percentage fall is different from gradually shorter cleaning sessions. It can indicate an ageing battery or a reporting problem, so compare the same room under the same settings.
Table of Contents
Start with these checks
- Charge fully and run one familiar room at the usual suction level.
- Note temperature, floor type and whether carpet boost was active when the percentage fell.
- Check for a dragging brush or wheel, then repeat once and keep the results for support.
What this looks like at home
If the drop happens only on a shaggy rug, increased load matters; if it happens on every surface, battery condition becomes more plausible.
Separate charging, workload and battery condition
| Check | What matters |
|---|---|
| Charging indicator | Confirm actual charging, not just physical contact with the base. |
| Repeatable room | Use the same surface and setting for a useful comparison. |
| Visible damage | Stop using damaged electrical equipment and seek appropriate support. |
A mistake to avoid
Do not repeatedly run the battery flat in an attempt to recalibrate it without manufacturer instructions.
Buy a part only after identifying the cause
Check the exact model and part reference before buying. If cleaning resolves the problem, a replacement may be unnecessary.
Browse Amazon UK results for robot vacuum model specific replacement battery. These are search results, not a verified recommendation for your particular machine.
What the result tells you
Keep the battery graph or before-and-after percentages from the repeatable room test. Explain whether the drop coincides with carpet boost or appears on a low-load hard-floor run as well.
Related guidance
- Robot Vacuum Battery Replacement UK: Cost, DIY vs. Pro & Best Options
- Robot Vacuum Maintenance Tips UK: Keep Your Cleaner Running Smoothly
Sources and scope
Checked on 9 September 2026. Manufacturer instructions apply to the models they name; use your own exact manual for button sequences, removable parts and cleaning permissions. Product specifications are advertised claims. Examples illustrate decisions and are not hands-on test results.