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The smart battery tester for musicians. Stop worrying about running out of juice.

When your performance depends on good batteries—or if you repair guitars—the Batt-O-Meter is a must-have in your gig bag or on your workbench!

The Batt-O-Meter not only indicates the percentage of life left in an uninstalled 9-volt, AA or AAA battery, but better yet, its smart circuitry works for installed batteries, too! Plug it into a pedal, effects box or active guitar: it measures the power being pulled from the battery, compares that load to the battery's remaining energy, and calculates the remaining hours of battery life.

Use it before you go on stage and stop worrying about running out of juice during your performance. It's a must for troubleshooting in the shop, too. Save time by checking battery life before you take things apart!

• Ends guesswork about battery replacement
• Saves you money—buy fewer batteries and get more life out of them
• Helps the environment—minimizes discarded batteries
• Fast, accurate and easy to use
• Compact—fits easily into a guitar case or tool box.

The Batt-O-Meter is switchable for alkaline, rechargeable and carbon zinc batteries. It's designed for circuits powered by a single battery (highest testable voltage is 10.23-volts), and includes a 1/4" test plug.

Note: The Batt-O-Meter will work with normal "negative ground" circuits, but will not work with "positive ground" pedals. If the black wire from the battery connects to ground (on the circuit board or jack), it's negative ground and the Batt-O-Meter will work.

The lighted display indicates battery type, voltage, percentage of battery life, hours remaining of normal use, and low battery status.

The Batt-O-Meter is powered by its own 9-volt battery (not included) with self-test function.

Customer Reviews

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  • 4.28 average rating from 18 reviews
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Not all it's cracked up to be.

(Customer's Reviews)

I purchased the batt-o-meter thinking what a great idea. Upon receiving it I checked a battery in my guitar with active electronics. The meter displayed 100% but it didn't show how many hours were left. I thought that odd but was ready for rehearsal so I figured I'd check it later. As we started playing within a half hour my battery died!

Later I checked a battery in another guitar that has been installed for several months. Again I got the 100% and no hours displayed. I contacted Stew-Mac thinking I might have a defective unit. They promptly sent another and upon testing the device I got the same results.

This is a great idea and if it worked I would keep it but if I can't rely on it and a battery fails during a performance I'm sunk. I gave it one star for the sheer ingenuousness of the device but otherwise it doesn't meet my needs.


Battery checker

(Customer's Reviews)

Great product ,very versitile


Room to improve

(Customer's Reviews)

This tester seems to work well on individual batteries and stomp boxes, however, like another reviewer said, you have to work to find the sweet spot when checking an installed active pickup battery. I tried it on a Fishman Matrix, Baggs Element, and a Takamine with factory electronics and got the same results. Close, and better than nothing or guessing, but no major cigar. Maybe the next version.

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