Multimeter use test battery
Analog multimeter has 1.5V BATT range and 9V BATT range for especially testing small battery. BATT range operation is different from DC voltage range. BATT range has accurate measurement and precise method to test AA and 9V battery. BATT range has internal low value resistor and when set to this range the current from test battery will flow through the resistor and there is some voltage across the resistor , the multimeter will display voltage from the resistor. But , DC voltage range is tested while test battery is open circuit (current does not flow) because DC voltage range has high input impedance so it is not a precise measurement to test AA and 9V battery , however , In many case it is still useful to test battery with DC voltage range (Rough or approximate measurement).
Step to check 1.5V 9V battery with multimeter.
1. Insert the red test lead to + terminal and the black test lead to COM terminal.
2. Turn range switch to 1.5V BATT for testing 1.5V AA battery and 9V BATT for testing 9V battery.
Battery test range ( BATT)
3. Reading the test result.
Good battery : the pointer will point at Good scale area.
Good or bad ? : the pointer will pint at Scale ? area , this condition battery can be used for low current consumption device , such as wall clock , but not suitable for device need power.
Bad : the pointer will point at Bad scale area , it's time to change a battery.
