Informative app note by TI talking about peak current draw from CR2032 batteries.
Most important findings:
- you can draw 30mA from a battery, and it doesn’t reduce battery capacity significantly (as opposed to 15mA).
- after half the capacity is used (100mAh), the internal resistance rises steeply from 20Ω to 1kΩ.
- use a big storage cap to prevent voltage droop during high draw episodes.