How to approve battery runtime and charging time
Approve runtime and charging-time claims against a written test method for the exact production battery and product. Fix the workload, settings, temperature, starting condition and endpoint, then review individual results from production samples before approving the wording. Arrange factory-side checks through Cambridge China Bridge.
Identify exactly what the claim covers
Ask the factory to identify the cell manufacturer and model, chemistry, rated capacity, pack arrangement, protection circuit and battery lot. Record the finished-product model, hardware and firmware versions. Keep battery labels, photographs and the relevant BOM together. A capacity label alone does not establish finished-product runtime.
Separate claims for a new battery from claims after use or storage. Record battery age, storage history and any conditioning before testing. Installation and wider battery sourcing questions belong in sourcing solar and battery products; this approval should establish the evidence behind the stated operating and charging times.
Define useful runtime before starting the test
Write a repeatable workload that reflects the intended use. Specify brightness, speed, suction or other output settings, connected accessories, wireless activity and the pattern of use and pauses. State whether the claim describes continuous operation or intermittent use. Test materially different modes separately rather than treating the easiest mode as representative.
Define the starting charge, how full charge is confirmed and any rest before operation. Specify ambient temperature, allow the product to reach that condition and log temperature during the run. Define the endpoint as loss of the agreed useful output or automatic shutdown, whichever your claim describes. A lamp still glowing faintly is not necessarily delivering its claimed useful runtime.
Measure charging time with the supplied equipment
Identify the exact adaptor, cable, connector and charging mode. State the power source, starting battery condition, ambient temperature and whether the product is switched off or operating. Agree when timing starts, such as when charging actually begins, and record interruptions. Use power adaptor and cable approval for the equipment combination.
Define what finished charging means: the full-charge indication, the controller terminating charge or another documented endpoint. Record the chosen endpoint and any difference between it and the displayed battery status. Test partial-charge and full-charge claims separately. Never bypass protective controls to obtain a shorter result; refer abnormal heat, swelling or repeated charging faults for investigation.
Approve production variation, not the best sample
Agree how samples will be selected from the production run and battery lots, how repeated tests will work and what results trigger rejection or investigation. Set the minimum acceptable runtime and maximum acceptable charging time before testing. For the wider sample and inspection process, use making bulk production match the sample.
Request individual results, including the shortest runtime, longest charging time, spread and failures. Keep sample identities, raw time records, temperature logs and equipment details. Do not let an average conceal units that fail the agreed limits. If measurement uncertainty could change the decision, ask the test provider to explain it before accepting a borderline result.
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Release the claim and control later changes
UK advertising requires an accurate product description. Approve the exact claim wording alongside its test report, with the relevant mode, temperature, charger and endpoint conditions visible beside the claim. Treat “up to” wording as something to substantiate, rather than permission to select an exceptional result. Keep performance approval separate from safety assessment.
Record who approved the method, results and wording, and which production configuration they cover. Require a review before changes to cells, pack construction, charging electronics, firmware or workload settings. Decide whether fresh testing is needed before releasing changed stock. Cambridge China Bridge’s staff in China can coordinate factory records and production checks against your agreed method.
Frequently asked questions
Can I approve runtime from battery capacity alone?
No. Test the finished product with the specified battery, workload, settings and temperature, stopping at the agreed useful-output endpoint.
Does a full battery icon prove charging is finished?
Do not assume it does. Agree the charging endpoint and record whether the indication matches the controller’s documented completion behaviour.
Can the factory give me only average runtime?
Ask for individual results and failures as well. Compare the shortest runtime and longest charging time with limits agreed before testing.
Should I retest if the factory changes the battery?
Review the change before accepting it. Ask whether the existing evidence still covers the revised product, and require fresh testing where performance could change.