Continuity, and resistance, along with diode terst, are meant only to be used on an unpowered circuit. The ranges are not designed to be used with power present. If you are trying to measure the resistance of a battery you need to select the voltage range, and apply a known load ( a resistor or lamp) and then measure the voltage unloaded, then the voltage with a lod, and measure the current draw separately, then calculate using those values. You cannot measure them directly.