Batteries go into a state of discharge when it reaches a voltage of 1.75 volts per cell or 10.5 volts in case of a 12 volt battery. Discharging the battery beyond this point may result in the battery reaching a point of no return. The lowest a 12V battery should be discharged to is 9.6V i.e 1.6V per cell. Continuous cycling to low voltage levels reduces the cycle life of the battery.

Most devices have a ‘low battery cut off’ voltage setting beyond which the battery is cut of from the circuit and stops discharging. If this is not present in a device using a battery, most certainly the life of the battery will be drastically reduced.