• Adafruit on Batteries
• PV Education on Batteries

• CR2032 Cell from Maxwell
• CR type cells, heat resisting, Maxwell

Battery capacity $C$ in $mAh$ or $Ah$.

Examples:

• $C = 1000\mathrm{mAh} = 1\mathrm{Ah}$
• Nominally: Continuous current of 1A for 1h. But: High discharge currents often lead to a reduced capacity!
• Better: 10mA for 100h.