The options for the cooling systemdepend on the usage cycles, selected cell, ambient conditions and what cooling systems are available for the installation. The high level goals are: 1. minimise the temperature gradient across the cell <3°C 2. minimise the cell to cell temperature <3°C 3. do not exceed cell maximum. There may also be a requirement to size a battery pack to have a passive thermal system, as such the heat capacity of the pack would need to be sized to suit. Of course, with all of the sizing you need to consider the pack ageing, fundamentally over time the battery will: 1. decrease in capacity 2. increase in resistance That.