1. Material System and Electrochemical Characteristics
The positive and negative electrode materials determine the voltage window, as different materials have different electrochemical stability ranges.

- Lithium Iron Phosphate (LFP) system: Typical charge cutoff voltage is 3.65V, discharge cutoff voltage is 2.5V (room temperature) or 2.0V (low temperature).
- Nickel Cobalt Manganese/Nickel Cobalt Aluminum (NCM/NCA) system: Typical charge cutoff voltage is 4.2V, discharge cutoff voltage is 2.75V–3.0V.
- Lithium Titanate (LTO) system: Typical charge cutoff voltage is 2.9V, discharge cutoff voltage is 1.5V.

Risks of overcharge/overdischarge:
- Overcharge can cause cathode structure breakdown, oxygen release, and electrolyte decomposition.
- Overdischarge can cause SEI layer rupture and current collector corrosion.

2. Safety Protection Mechanism
A multi-level protection design ensures battery safety:
- Charge termination voltage: e.g., 3.65V (LFP), when reached, the BMS terminates charging.
- Primary overcharge protection: e.g., ≥3.8V (LFP), forced charge termination.
- Secondary overcharge protection: e.g., ≥4.0V (LFP), BMS lock to prevent thermal runaway.
- Discharge termination voltage: e.g., 2.5V (LFP), stops discharging.
- Primary overdischarge protection: e.g., ≤2.0V (LFP), forced discharge termination.
- Secondary overdischarge protection: e.g., ≤1.8V (LFP), BMS lock requiring manual repair.

3. Temperature Adaptability
Cutoff voltages are adjusted depending on the temperature:
- T > 0°C: 2.5V (LFP).
- T ≤ 0°C: 2.0V (LFP), to avoid premature cutoff caused by polarization.

4. Lifetime and Performance Optimization
- Higher charge cutoff voltage (e.g., increasing LFP from 3.65V to 4.0V) accelerates capacity fade.
- Lower discharge cutoff voltage (e.g., below 2.85V for LFP) leads to loss of active lithium.
- Formation process: Pre-charge cutoff voltage must be controlled within the SEI formation range (e.g., 2.8–3.0V) to avoid impurity reactions.

Conclusion
The determination of cutoff voltage is the result of material characteristics, safety, lifetime, temperature adaptability, and compliance with standards. Manufacturers such as EverExceed validate these boundary values through electrochemical testing, and the BMS enforces multi-level protection to ensure batteries operate within a safe window.

Reference link: How Are the Charge and Discharge Cutoff Voltages of Lithium-ion Batteries Determined? - OFweek Lithium Battery Network