A heated vest does not have one fixed battery runtime. The same garment can operate for different lengths of time depending on its battery, heat setting and heating system. That is why an “up to” figure is useful only when the conditions behind it are clear.
For brands developing heated apparel, runtime should be treated as a measurable product specification—not a number selected for a product headline.
Start with battery energy, not just mAh
Battery capacity is often shown in milliamp-hours (mAh). On its own, that figure does not describe how much energy is available when comparing batteries with different voltages.
Watt-hours (Wh) provide a more useful starting point. Nominal battery energy can be calculated as:
Watt-hours = battery voltage × amp-hours
For example, a battery rated at 5,000 mAh has a capacity of 5 Ah. Its energy in Wh still depends on its rated voltage. The energy the garment can actually use may be lower because of power conversion and other system losses.
Heating power changes the result
The garment’s heating elements draw electrical power, measured in watts (W). As a simple planning estimate:
Runtime ≈ usable battery energy (Wh) ÷ average system power (W)
If a system had 20 Wh of usable energy and drew an average of 10 W, the estimate would be about two hours. This is an illustration, not a runtime claim for a particular vest. Real systems may change their power draw as the control setting operates, and testing is needed to establish the finished product’s runtime.
“Low,” “medium” and “high” need separate results
A vest generally uses more energy when it is delivering more heat. Runtime should therefore be reported for each setting with the same specified battery.
If the garment allows heating zones to be controlled separately, record which zones were active during the test. “Up to eight hours” could describe one setting and zone configuration; it does not necessarily describe continuous operation with every zone on high.
This detail matters to customers comparing products and to brands preparing accurate instructions and marketing materials.
What else should a brand test?
A useful runtime test record identifies the complete setup, including:
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The battery model, rated voltage and capacity
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The garment model and heating-zone configuration
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The selected heat setting
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The test environment
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The point at which runtime is considered to have ended
Testing should use the finished garment and its intended power components. It is also worth checking whether the battery pocket, connector and controls remain comfortable and accessible throughout normal wear. A runtime figure is only one part of a usable product.
Write a claim customers can understand
A clear product description might state:
“Runtime tested with the specified battery: X hours on low, Y hours on medium and Z hours on high, with all listed heating zones active.”
The values should be filled in only after testing the actual configuration. If a product is sold without a battery, say so and identify the compatible power requirements rather than implying that every power bank will deliver the same result.
At TOPFENG, heating zones, power configuration and garment construction can be developed around a project’s intended use. Learn more about our heating technology, or share your target garment and runtime requirements through our OEM & ODM page.