When a battery is discharged, its voltage will gradually decrease until it reaches a minimum operating voltage. This is called the End of Discharge Voltage. If a battery-powered device continues to pull current from a battery below the EDV, the battery may be damaged or degraded to the point where it can not be recharged or used again. Integrating the passed charge during the discharge process measures the capacity Qmax that can be delivered until EDV is reached. The Voltage profile during a typical low rate lithium ion battery discharge is illustrated above. As the capacity approaches the EDV point, if additional current is drawn, the output voltage collapses toward zero very quickly. So, even if it were “safe” to do so, there is very little additional capacity that could be delivered by going past the EDV point anyway.