Intensity Levels and Runtime by Level: Reading the Spec Sheet

What the term actually covers

An intensity level is a defined operating state, not a vague "stronger" or "gentler". On a kneading neck massager it is usually a motor speed, sometimes combined with a reverse direction or a pause pattern. On a pulse design it is a waveform and a pulse rate. Runtime is the operating time the battery supports at that state. The two are separate columns: a level tells you what the unit does, runtime tells you how long it can do it at that setting.

The common shortcut is to print one total runtime on the box. That number was produced at one specific state, and the state is rarely named. A buyer comparing two quotations is comparing two different conditions, not two products.

A third term sits beside them: duty cycle. In a kneading unit the motor may pause between runs, so the runtime at a given level depends on how often the motion resumes. A duty-cycle change can extend the runtime without changing the battery at all.

How to read the evidence

Every runtime figure needs four companions: the level, the motor state, whether a heating function was on, and the measurement method. A battery that reads one figure at the lowest level and another at the highest is not a contradiction; it is a condition. Ask which condition produced the headline number and request the same figure for each level.

A second question is the test boundary. Runtime measured to a fixed cut-off voltage is not the same as runtime to a "low battery" indication, and neither is the same as usable runtime under intermittent use. Ask what the cut-off was and how the run was started, at full charge, at a set ambient, at a fixed strap position.

Comparison table

Level	What it changes	What it does not change	What to ask for
Low	Motor speed, duty cycle	Battery capacity	Runtime at this level
High	Motor speed, drive current	Cell chemistry	Runtime plus current
Pulse mode	Waveform, pulse rate	Contact area	Method and cut-off
Heating on	Current draw, heat source	Motor speed	Combined runtime
Heating off	Current draw returns	Contact area	Combined runtime
Auto mode	Alternates states	Cell chemistry	Mixed runtime record

Each row is a separate measurement. A specification that gives one number for all five rows is a generalisation, not a record.

Intensity is not the same as runtime

Intensity ≠ runtime, and neither is a fixed property of the battery. A higher level draws more current and shortens the run; a heating function draws current independently of the motor. Neither the level nor the runtime can be read from the battery capacity alone, because the drive electronics and the heating element both sit between the cell and the user.

The boundary also runs the other way. A long runtime at the lowest level does not mean the unit is gentle by design; it may simply be running the motor at a low duty. State the level with the figure.

A third boundary is between firmware and hardware. A level count quoted on the sample may not be the level count in the production firmware. Ask for the firmware version alongside the level table, because a level added in firmware changes the runtime record without changing the cell.

The level table should also be read against the battery identifier. A runtime figure quoted for one cell is not evidence for another cell of the same family, because the internal resistance and the discharge curve differ. Ask which cell identifier the level table was produced with, and request the same table repeated with a second cell if the production cell is not the same.

A second habit belongs beside the table: ask what the user sees when the level changes. A unit can report the same number of levels while the underlying states differ in waveform, direction or duty cycle, and a buyer comparing two quotations should ask for the state table rather than the level count. The level count is a headline; the state table is the record.

Reading the level table at incoming inspection

The level table becomes useful at incoming inspection only when the condition is written into the line. Ask for the runtime at each level with the heating state, the cut-off voltage and the band position beside it, so the same table can be reproduced on a batch sample. A figure quoted as a single number for all levels cannot be reproduced, because the run that produced it was run once at one state.

The second use is comparison. Two quotations can be placed side by side on the same level definition, the same cut-off and the same heating state, and only then does the runtime difference mean something. A buyer who compares a runtime at the lowest level against a runtime at the highest is comparing two conditions and calling the difference a feature. Write the state beside the figure on both quotes, and read a missing state as a question rather than as a number.

Questions to ask a supplier

How is each intensity level defined, by speed, waveform, direction or duty cycle?
What runtime was measured at each level, and was the heating function on or off?
What cut-off voltage was used, and how was the run started?
How many levels exist in the final firmware, and does the sample match the production firmware?
What happens to runtime when the pad surface or a fully charged cell is fitted?

Common mistakes buyers make

Comparing headline runtime across quotations without the level. Ask for the per-level table.
Assuming battery capacity alone predicts runtime. Drive electronics and the heating element change the draw.
Taking a sample firmware level count as the production count. Firmware can change before the first shipment.

Each is caught by writing the level definition and the measurement condition into the purchase order and by re-testing a batch unit.

Next step

Request a per-level runtime table with the test condition named, and send it with your quotation request via contact.