User Cases

A battery cell ages when just sitting on a shelf, ok everything ages just sitting on a shelf, but a battery cell can age quite quickly at elevated temperatures.

The reason for making this point is that when designing a battery pack the user cases need to consider the complete time history and not just the drive/duty cycles for when the pack is being charged/discharged.

Hence when predicting the ageing profile of a battery pack it is best to think of user cases.

In these user cases you need to consider:

  • charge profile
  • discharge profile – what we might normally call the drive cycle
  • rest periods
  • temperature at all times over the lifetime

If your product is new or novel it might be necessary to create synthetic user cases. It is ok to create an average use case, but also create the extreme use cases. Remember that the toughest user cases may not be those with the highest energy throughput.