*Take Lishen 2.6Ah 18650 as an example,

1.The discharge termination voltage of the cell must be higher than 2.75V;
2.The battery discharge temperature range is -20℃~+60℃, according to the specified current (see 3.8 in the specification). During the discharge, if the surface temperature of the battery exceeds 70℃, the discharge must be terminated.
3.If the voltage of the single battery is lower than 2.75V, the battery is considered to be over-discharged and cannot be used continuously.