Keith McMillen Instrument BATT-O-METER
Battery Tester


Our Price: $22.05List Price: $29.95
You save 26%! (Low Price Guarantee)
In Stock


  • saves you from risk and stress before a performance
  • saves you money by extending the life of each battery
  • save the environment by reducing the number of discarded batteries


Quickly and accurate measure:

  • how many volts a battery is delivering
  • hours left before the device runs out of power





(Requires 9 volt battery, not included)

Frequently Asked Questions:

What makes Batt-O-Meter work?
Stomp boxes and instruments use a standard stereo 1/4” phone jack and devices sense the insertion of the 1/4” mono plug to turn on the power. Batt-O-Meter measures the Voltage and Current to let you know how many more hours the battery will work. A micro-processor within the unit allows the device to intelligently determine the different loads that can be put on the battery and calculate the power in hours remaining. This eliminates the need for extra buttons and adaptors, and makes the Batt-O-Meter simple to use.

What devices does the Batt-O-Meter work with?
The Batt-O-Meter works with almost any active instrument pickup or effects unit (stompboxes and other floor effects) that require a 9 volt battery to operate, and is turned on when a standard 1/4" cable is plugged into it. The Batt-O-Meter can test stand-alone batteries: 9V, 1.5V (AAA, AA), and 3V. It does this, by automatically placing the battery under an appropriate load to simulate real world usage. It works with Alkaline, Rechargable (ie. Lithium-ion, NiCd, NiMH), and old school Carbon-Zinc batteries.

What is the Power Probe?
The Power Probe is not your normal 1/4 inch plug. It is a gold plated 1/4" plug specially designed to allow the Batt-O-Meter to test the unit without turning it on. This allows for far more accurate readings with a wide array of devices. In certain cases, for example with certain models of acoustic/electric guitars, the probe must be used discerningly, i.e. it must be inserted half or three-quarters of the way into the input jack to get an accurate reading.

Can the Batt-O-Meter check its own battery?

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