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

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Item # 0323
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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.

Ratings & Reviews


  • Based on 18 Reviews
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Not all it's cracked up to be.

By Terry Angelli from Malden, MA 
(Customer's Reviews) Sunday, September 21, 2014

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

By art from sydney nova scotia
(Customer's Reviews) Wednesday, March 12, 2014

Great product ,very versitile

Room to improve

By Lefty S from Austin, TX
(Customer's Reviews) Thursday, June 14, 2012

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.

swiss army knife...for batteries

By Dani Guitar Shop from Firenze, IT
(Customer's Reviews) Wednesday, May 23, 2012

I've found this tiny box amazing, not only for simply measuring batteries. The top feature is to show customers how much battery drain is their device using in real time! Gives a really professional point of view on your job: a must-have.

Doesn't work in a positive ground pedal

By Loren from Spain
(Customer's Reviews) Wednesday, May 23, 2012

It's a very useful tool anyway, but you need to remove the battery in positive ground fuzzes, etc... Perhaps a diy cable reversing ring and ground should work?,(not sure)

Handy Money Saver

By David Deaton from Arkansas
(Customer's Reviews) Saturday, January 21, 2012

Makes checking batteries installed in instrumements and pedals a snap. Instead of changing batteries just to "be safe", use this. Can pay for itself in no time. Certainly can't expect it to be exact, but more of a benchmark tool. When the number gets low, change the battery. Simple.

This gizmo is a gig-saver!

By erieknight5 from Cleveland
(Customer's Reviews) Friday, September 09, 2011

Make sure you save the instructions. This device has some neat features. (You may need to review) The Batt-O-Meter has already saved me from battery failure-related catastrophies 4x in only 2 gigs. Easy to use for 9V. It even reads the batteries while installed in the instrument or stomp box. Shows battery power remaining. Reads the rechargeable ones too!

must have

By Raj Pereira from dubai, UAE
(Customer's Reviews) Friday, July 08, 2011

want to save money and avoid embarrassment in the middle of a gig , you must have this in your gig bag ...


By jerry c metz from canada
(Customer's Reviews) Wednesday, May 11, 2011

I have other battery testers but I bought this one because it just plugs into my guitar instead of having taking my batteries out. I don't find it very accurate. Get different readings all the time. Not happy with it at all, I feel I can't depend on it.

Nearly excellent.

By Gilbert from France
(Customer's Reviews) Thursday, February 24, 2011

Why? Because it works on all my instruments but my Ovation guitar with nylon strings. Otherwise, I'm happy with it.

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