How to Test a 9-Volt Battery

You can use a digital multimeter to determine 9-volt battery voltage.
••• Polka Dot Images/Polka Dot/Getty Images

Testing a 9-volt battery will let you know if it is out of electrical energy. A battery produces and stores energy for future use by a chemical reaction between two different metals. The energy in batteries creates a voltage difference between their positive and negative terminals. The square 9-volt battery has the size necessary to create a voltage of nine volts. When the 9-volt battery is installed in a device, the voltage difference between its terminals causes electrical energy to flow. After time, the battery will become worn out and cannot create the nine volts it could when first manufactured.

    Plug the red lead of the multimeter into its positive port. Connect the black lead of the multimeter into its negative port. On some multimeter models, the negative port is called "common" or "ground." Each lead has a metal probe on its other end.

    Turn on the multimeter. Rotate the measurement dial to the direct current (DC) voltage setting. On most multimeter models, DC voltage is denoted by a capital letter "V" with straight lines above it.

    Touch the red multimeter probe to the positive terminal of the 9-volt battery. Touch the black multimeter probe to the negative terminal of the 9-volt battery. The voltage of the battery will appear on the multimeter screen. If the measured voltage is not at least eight volts, replace the battery.

Related Articles

How to Diagnose Amperage Draw With a Multimeter
How to Convert 12 Volt to 6 Volt
How to Charge a 12V Battery With a DC Motor
How to Calculate Millivolts to Amps
Will Batteries Discharge if You Throw Them in a Bag...
How Do Batteries Work? Parts, Types & Terminology (w/...
How to Convert Ohms to Kilowatts
How to Measure Wattage With a Multimeter
How to Wire a Battery in Series
Energizer Watt-Hour Battery Specs
How to Calculate Induced Armature Voltage
Lithium vs. Lithium Ion Batteries
Parts of a Battery
DIY Very Simple 60-Hertz Oscillator With a Quartz Circuit
How to Build DC to AC Power Inverters
How Does a DC Power Supply Work?
How to Charge High Voltage Capacitors
How to Use a 12V Diode to Prevent Backfeed
What Is a Flyback Diode?
Circuit Breakers Compatible With an Electrical Panel