I'm new to Li-Ion battery design, so please don't judge if I make stupid mistakes. In our IoT solution we use a LIR2032 Li-Ion cell. Here is some information from it's datasheet:
Nominal Voltage: 3.6V
Nominal Capacity: 35 mAh
Maximum Capacity: 40mAh
Internal resistance: ≤600mΩ
- When the battery is used on load, it is recommended to design a charge/discharge protection circuit for the battery.
- In a temperature of 20±5°C, CC charge 0.2CmA / voltage up to 4.20V; Then CV charge. Terminate charging when the charging current value is less than 0.05CmA. Rest for no more than 10 minutes, Discharge CC at 0.2CmA to 2.75V.
- Temperature 20±5°C, CC charge at 1CmA to 4.20V; turn to CV charge; Terminate charging when the charging current value is less than 0.05CmA, rest for no more than 10 minutes, then at 1CmA CC discharge to 2.75V.
- When the battery is stored and not used under room temperature for over 6 months, it needs to be recharged by the procedure below: Discharge by CC mode at 0.2CmA to 2.75V, then rest for 5 minutes, Charge by CC mode at 0.2CmA to 4.20V limit, then change to CV charge mode, Cut off the charge when the charging current is less than 0.05CmA.