How to discharge your industrial-grade lithium-ion batteries to optimize their lifespan

1: Lower the C rate when discharging to optimize your battery’s capacity and cycle life. Strong rates increase the battery’s internal resistance. The battery will have to strive to deliver high current and use more power to keep the same voltage level, which will therefore make it age faster.

2: Be mindful of the temperatures at which the battery is being discharged. At extreme temperatures, electrode and electrolyte no longer have the optimal shape (it contracts at low temperatures and expand at high temperatures) to enable efficient lithium-ion exchanges.

3: Favorize a partial depth of discharge (DoD). A partial charge and discharge will reduce stress and prolong battery life. It is recommended to avoid full cycles and stay between 100% and 50% DoD (0-50% SoC).

4: Make sure to proceed with periodic balancing if there is more than 1 cell in your battery pack. When several cells are connected in series in a battery, an imbalance might occur. The cells might be charged to different state of charge (SoC) levels, the impedance (internal resistance) might vary from one cell to the other, the cells capacity might differ from one cell to the next, etc. You will need to re-balance them from time to time in relation to each other with the help of the BMS so that one cell does not wear out more than the other.

5: Monitor the State of Health (SoH). The State of Health reflects the general condition of a battery and its ability to deliver energy over time. It gives an indication of how much of the battery’s lifetime available energy has been consumed, and how much is left which helps you to anticipate issue or when the battery needs replacing.