Battery runtime fade

Researched from published specifications and owner reported figures · Standard and convention

Quick answer

A lithium vacuum pack that delivers about 80 percent of its rated runtime after two to three years has aged normally, not failed. Runtime well below that, on a machine whose filter is clean, is the point where a replacement pack is the cheaper fix than a new vacuum. Remember that the rated figure is the eco mode number, and boost typically runs the pack down three to four times faster.

The calendar and cycle loss figures are conventions drawn from lithium ion behaviour. The rated runtime is whatever the manufacturer published for your machine.

Battery runtime fade Standard and convention
The headline figure from the manual or the listing, which is the eco mode number.
Time it from a full charge until it cuts out.
Runtime against the fair target 53%
Fair target for eco mode60 min
What you measured32 min
Expected from calendar ageing alone90% at 2.5 years
ReadingWell below its age
  • A drop this large is usually either a pack near the end of its life or a machine working against a blockage. Both are worth checking before buying anything.
  • The filter has not been cleaned recently. A restricted filter makes the motor draw more current for less result, which reads exactly like a tired battery. Clean it and measure again before ordering a pack.
  • A pack that is swollen, hot to the touch or leaking is finished and is not a repair. Take it to a battery recycling point, never to household waste.
How it works: expected remaining = (1 - yearly calendar loss)^years, compared against measured runtime / rated runtime Cycle count matters too, but almost nobody tracks it, so age is the practical proxy.

Replacement packs, and the machines if it comes to that

Vacuum packs are model specific and a brand match is not a model match. Check the part number on your old pack against the listing.

What this tool does and does not do

It works through the checks in the order a service technician uses, and it tells you what each outcome would mean. It cannot see your machine, so nothing here is a diagnosis of one particular vacuum. Treat every result as a list of things to rule out, and let the part number printed on your own machine have the final word.

No vacuum on this site has been tested by us. Every figure comes from a published manufacturer specification, a defined unit, or a widely used service rule of thumb, and each page says which of those it is using.

Safety

A damaged lithium pack is not a repair job

Swollen, hot, leaking or physically damaged means finished. Stop using it, keep it away from anything flammable, and take it to a battery recycling point. Lithium cells must never go in household waste.

Common questions

Why is my runtime nothing like the box figure?

Because the box figure is almost always the eco mode number, measured with the non powered tool fitted rather than the motorised floor head. Running in boost with a powered head can cut that figure to roughly a quarter. Neither number is dishonest, they simply describe different conditions, which is why this tool asks which mode you measured in.

At what point is a new battery worth it instead of a new vacuum?

When the machine is otherwise sound and a pack costs well under half of what you would spend replacing the whole thing. Batteries are consumables on cordless vacuums in the way tyres are consumables on a car, and a great many working machines are thrown out because the pack reached the end of its life rather than the vacuum did.

Does leaving it on the charger damage the battery?

Not on any machine made in the last decade. The charge controller stops at full and holds there. What genuinely ages a pack is heat and being stored empty for long periods, so the thing to avoid is a garage that swings between freezing and baking, not the dock itself. Room temperature storage is what matters.

How many charge cycles should a vacuum battery last?

Somewhere between three hundred and six hundred cycles to eighty percent of original capacity is the usual range for the lithium cells used in household machines. Very few owners track cycles, so age is the practical proxy: most packs are noticeably down by their third or fourth year of regular use, and that is normal wear rather than a defect.

Can a dirty filter really look like a dead battery?

Yes, and it is one of the most common false alarms. A restricted airway makes the motor work harder for less airflow, so it draws more current and the pack empties sooner while the machine also picks up worse. Both symptoms point at the battery, and both disappear when the filter is cleaned. Always rule that out first.

What do I do with the old pack?

It goes to a battery recycling point, never into household waste or kerbside recycling. Lithium cells that are crushed in a collection truck start fires, and this is a genuinely common cause of them. Most hardware stores and many municipal recycling centres take them free. A swollen or damaged pack should be kept away from anything flammable until you get there.

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About this page

Every figure here comes from published manufacturer specifications, owner reported measurements and repair documentation, and each is labelled as either a standard or a convention. This is researched general information to help you diagnose and plan, not professional advice, and it cannot tell you what is wrong with one particular machine. Your own manual and the part number printed on your machine are the final word.