Designing battery packs is a complex scientific and engineering challenge, where performance, lifetime, and cost must be balanced, requiring the optimisation of many contributing factors. The choice of cell, optimisation methods, and packaging and manufacturing considerations are all open to over and under-engineering, in the absence of in-depth understanding of their repercussions on the wider systems.

Choosing the optimum cell is challenging due to the variety of options in chemistry, form factor, and energy density. Datasheet information and many standard characterisation tests will be shown to be of little use for this purpose. A comparative study between six commercially relevant cells will be presented, focussing on the lessons learnt, including recommendations for representative tests at single cell and small module level.