How to Test a Battery Using a Digital Multimeter

A digital multimeter will tell you if your batteries are capable of powering your household gadgets.

You can use a digital multimeter to test the voltage of any battery. If you have batteries around the house or office and are unsure if they will provide adequate power, a digital multimeter will help. Testing your batteries can be done in minutes. Common household batteries range from 1.5 to 9 volts.

Things You'll Need

• Digital multimeter

Instructions

1. Set up your digital multimeter. Place the black probe plug into the COM port and the red probe plug into the V port (usually red). The probes can either be needle type or have alligator clips.

2. Turn on your digital multimeter. If your meter has a dial, turn it from the "Off" position to "DC" voltage position. The DC voltage position has the V with the straight and dashed line over the top.

3. Place the black probe lead on the negative (-) side of the battery. Then place the red probe lead on the positive (+) side of the battery. On a typical alkaline battery -- such as size AA, AAA, C or D -- the plus side has the bump and the negative side is flat. For a 9-volt battery, the positive and negative connections are both on top; the positive side is the smaller, more round connection.

4. Read the voltage on your digital multimeter. This is the DC voltage output coming from the battery. AA, AAA, C and D batteries will each produce 1.5 volts. New alkaline batteries will read slightly higher values. Any voltage over 1.5 volts or 9 volts is good. Rechargeable batteries are many times rated lower than 1.5 volts for size AA, AAA, C and D. They often range from 1.25 to 1.4 volts. Read the jacket on the battery to see what the battery voltage is rated. Your digital multimeter will help you to read the battery voltages to test the batteries so you know what is good.

Tips & Warnings

• Some electronics devices may work with a battery with less charge. Make sure you always use the same brand of batteries -- each with an equal charge. If you use different battery types, you are more likely to get battery acid leakage on your electronic device.

• Never try to recharge standard alkaline batteries since they may explode. Only rechargeable batteries can be recharged using an approved charger.

References

• Southern Methodist University Department of Physics: Digital Multimeter