Instructables
Picture of Cute AA voltmeter
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Ever wonder if those AA batteries are any good.  You could get out the voltmeter and check them.  That can be a hassle.  Sometimes it would be nice just to check them quickly.  In this instructable you will create a cute little AA voltmeter. By the way if soldering is not your thing, you can get the finished product from https://tindie.com/Paulware/cute-aa-voltmeter/. 

Step 1:

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Get the parts.  Here are some links and prices you can also order this as a finished product from https://tindie.com/Paulware/cute-aa-voltmeter/
These parts are available from ebay for $7.44

$3.60 Blue voltage readout
http://www.ebay.com/itm/280928770982?var=580118175716&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

$2.85   3XAA battery case with switch
http://www.ebay.com/itm/1pcs-3xAA-3AA-4-5V-DC-Power-Battery-Case-Box-Holder-Switch-Cover-with-Cables-UM9-/290737949440?pt=LH_DefaultDomain_0&hash=item43b1550b00

$0.99 usb cable
http://www.ebay.com/itm/NEW-USB-2-0-MALE-AM-M-TO-FEMALE-F-EXTENSION-CABLE-/270987217823?pt=US_USB_Cables_Hubs_Adapters&hash=item3f1818cb9f

Step 2:

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Drill/Dremel  a hole for the usb cable.

Step 3:

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Connect the usb cable to your laptop or usb power supply.  Using a voltmeter determine which cables are 5V and GND on the usb cable.

Step 4:

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Connect the usb cable 5V to Red cable on tiny meter
Connect the usb cable GND to Black cable on tiny meter
Connect Blue cable on tiny meter to AA +
Connect AA - switch output to usb cable GND

Step 5:

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Test out circuit.  Then solder and glue liberally. 
If soldering is not your thing, you can also get this product from https://tindie.com/Paulware/cute-aa-voltmeter/ for $12.00 (free shipping in US).
 
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useraaaaa2 years ago
1.2voltmeter which requiries 5v
paulware (author)  useraaaaa1 year ago
I created a version on Tindie that uses a built-in power supply: https://tindie.com/shops/Paulware/digital-voltmeter-for-aa-and-aaa-1/
pudtiny2 years ago
Great little device, but I am not sure having to find power for this would be any quicker than picking up a meter to do the test
paulware (author)  pudtiny2 years ago
(removed by author or community request)
Now its more useful you should add its other uses
paulware (author)  pudtiny1 year ago
Thanks for the comments!
I created a new version that has its own power supply, available here: https://www.tindie.com/shops/Paulware/digital-voltmeter-for-aa-and-aaa-1/