My Shure battery powered product seems to use batteries too quickly. How do I measure the device's current draw to make certain it meets specifications?
Here are step by step instructions:
- Determine the proper current consumption (draw) for your product. Look in the User Guide for this specification or contact Shure Applications Engineering. For this example, assume the device is a Shure wireless transmitter that uses AA batteries and that the specified current draw is 180 mA (milliamps).
- From a local electronic supply store, obtain a digital multimeter, some test leads with small alligator clips, and fresh AA batteries.
- Set the multimeter to mA and make certain to connect the leads to the correct jacks on the multimeter.
- Insert one AA battery into the transmitter.
- Connect one of the test leads between the remaining spring in the battery compartment and the black lead going to the multimeter.
- Lay the positive end of the second battery into place.
- Hold the red lead from the multimeter onto the negative end of the second AA battery.
- Power up the Shure device and measure the current draw. Current draw typically can vary by as much as +/- 20%. A current draw within this +/- 20% window is acceptable.
- To calculate how long a fresh battery should last, divide the current capacity of the battery by the current draw of the device. In this example, a AA alkaline battery has a current rating of 1400 milliamp hours; the device draws 173 milliamps. 1400 divided by 173 equals 8 hours of operation. This would be the maximum operational time that the battery could supply; it will be likely be less.