A Ni-MH cell is nominally 1.2V and its voltage sags gradually as it discharges. A Type-C lithium cell holds a regulated 1.5V until it is nearly empty, then stops. Devices that measure battery level by voltage will read the lithium cell as full right up to the moment it dies — which is fine in a remote and annoying in a camera flash.

The other difference is workflow. Ni-MH needs a charger; the Type-C cell needs a cable and a free USB port. For a venue managing forty cells, the charger wins on throughput. For a consumer with four, the cable wins on convenience.

Cost separates them further: Ni-MH is considerably cheaper per cell and per cycle. Buy the lithium cell for the voltage behaviour or the convenience, not because it sounds more modern.

Use this checklist

  • Check how your device measures and cuts off on voltage
  • Test runtime in the finished product, not on a bench
  • Compare cable charging against a multi-slot charger for your volume
  • Ask for the transport documents on lithium models