The cut-off voltage of the discharge depends on the size of the discharge current. See "Discharge Characteristics" for the relationship between discharge current and recommended cut-off voltage. Do not discharge the battery below the recommended cut-off voltage. When batteries are discharged below this cut-off voltage, they may be over-discharged

It is important to avoid excessive discharge. Charge the battery immediately after it is discharged.

Even if the discharging of the battery is stopped before the battery reaches the recommended cut-off voltage, the battery may deteriorate if it is stored instead of charging after discharging.

If the equipment does not have a circuit (or device) to prevent over-discharge (and weak current), the battery may be over-discharged, and its capacity may not be restored after charging.

When the battery is in a discharged state, it may be difficult to charge the battery due to the increase in internal resistance.