A mobility battery carries a person through traffic, ramps and daily life, so its validation combines vehicle-level ISO 7176 testing with cell-level safety and transport evidence. Paper C maps that programme for a nickel-metal hydride traction pack: range and endurance tests, electrical and climatic validation, cell safety, cycle-life aging and the documentation required to ship and travel.
The pack is discharged through the controller and motors over repeated ISO 7176-4 reference cycles, recording Wh/km, delivered range and controller cut-off voltage. Crucially, testing repeats at the corners — maximum user mass, simulated gradient, low temperature, and aged cells at 80 % capacity — because a range claim that holds only for a light driver on a level floor at 25 °C is misleading. Voltage sag at hill-climb current is measured against the controller's low-voltage cut-off to rule out premature power loss with energy still in the pack.
Mobility packs live under a seat, exposed to vibration, kerb strikes, humidity and outdoor temperature. Validation combines the ISO 7176-9 climatic sequence (operating and storage temperature, moisture) with vibration/shock on the welded pack, checking for tab cracks, loosened interconnects and insulation integrity. IEC 62133-1 adds cell-level cases — external short at ambient and elevated temperature, overcharge, forced discharge, mechanical and thermal cycling — validating the safety vent and confirming NiMH's controlled failure behaviour in an occupied vehicle.
NiMH reaches its 80 % end-of-life after roughly 500–1000 cycles depending on depth of discharge and temperature; for a chair discharged daily, that maps to a service interval expressed in both cycles and years. Development cycling at the real daily profile, combined with elevated-temperature storage, sets the fade curve and the justified replacement recommendation. Because NiMH fades gradually, the user experiences slowly reducing range — a predictable service signal rather than sudden failure.
UN 38.3 clears manufacture-to-factory shipment. For end-user air travel, documentation should state watt-hours and chemistry: spare uninstalled lithium packs are restricted (around 100 Wh, up to 160 Wh with operator approval), while installed mobility batteries and NiMH packs follow different, generally simpler rules — a point customer service teams should be able to explain precisely.
Weijiang Power supplies high-rate NiMH cells and 24 V custom traction packs for mobility OEMs with IEC 62133-1 and UN 38.3 evidence, welded vibration-robust construction and support for ISO 7176-4 range validation. Send your reference-cycle Wh/km, maximum load and range target and we will engineer and document a pack that meets them to end of life.
