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How to test an alkaline 1.5V AA battery? — Parallax Forums

How to test an alkaline 1.5V AA battery?

Hi All,

I've been collecting used batteries from the wireless microphones at church. I'm sure some of them can be put back into the "used" bucket for relatively confident usage, and others need to go bye-bye.

The question is how to effectively test them for that decision.

I'm guessing they would require a current load equal to the microphone requirements and then observe the voltage.

And another question would be, how long to load the battery for an effective test?

One more question would be, at what voltage is a 1.5V AA battery considered "dead"?

Thanks for any input.

Comments

  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2021-04-26 03:08

    Cheaply designed equipment may not use the battery effectively and they may drop out when the battery voltage is down to 1.25V. Other equipment is either designed to run at much lower voltages or use a buck/boost regulator to get the most out of the battery.

    I use a cheap battery tester which is powered by the battery itself and loads it too of course. But if I read 1.3V I normally replace them. The voltage on an AA won't really droop much unless it's a decent load.

    A word of caution. I have seen people buy packs of these "Super Heavy Duty" batteries but they are nothing more than the old carbon-zinc battery, but slightly better and compared to the old batteries from 50 years ago they may indeed be better but they are horrible for battery powered electronics because the voltage starts to drop and continues to drop as they are used. Totally useless!

    Btw, wireless mice and keyboards and remotes do tend to in general work down to much lower voltages and so you can expect a long life from the batteries.

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,980
    edited 2021-04-26 03:08

    Drop the battery, cathode end down, onto a hard surface. If it bounces, the battery is dead; otherwise, it still has some life remaining.

    -Phil

  • ercoerco Posts: 19,925

    @"Phil Pilgrim (PhiPi)" said:
    Drop the battery, cathode end down, onto a hard surface. If it bounces, the battery is dead; otherwise, it still has some life remaining.

    -Phil

    Interesting PhiPi! Never heard that. I googled and found this, which explains and disputes.

    https://www.mcgill.ca/oss/article/did-you-know-general-science/do-dead-batteries-really-bounce-and-charged-ones-not

  • @"Phil Pilgrim (PhiPi)" said:
    Drop the battery, cathode end down, onto a hard surface. If it bounces, the battery is dead; otherwise, it still has some life remaining.

    LOL, but the ANSI standard drop test wasn't really spec'd for modern alkalines and electronics :smile:

  • We used the drop test in the robotics class I was teaching, where we were going through the ActivityBot AAs like candy. Of course, it's not perfect, but it was quick and good enough to know which ones to keep and which to throw out.

    -Phil

  • YanomaniYanomani Posts: 1,166

    Here is a news note, dating back to 2015, showing the results from many test conducted by a group of professors at Princeton that resulted into an article, published at the The Journal of Materials Chemistry A, March 2015 edition.

    Interesting readings...

    https://princeton.edu/news/2015/03/30/battery-bounce-test-often-bounces-target?section=topstories

    https://pubs.rsc.org/en/content/articlelanding/2015/ta/c5ta01576f#!divAbstract

  • Cluso99Cluso99 Posts: 17,710

    I just test with a meter. It’s it perfect but good enough for us. Never tried the drop test.
    Considered as follows (Energiser)

    1.5V new
    1.4V good for other things
    1.3V can still squeeze a little more

    < 1.3V throw

    We go through a lot as we use them in remote mics for our video shows which run for about an hour. If there are not 3 of 3 bars showing on the displays we replace them as we cannot afford to lose a mic during the show.

  • Sure it's good to be safe than sorry but we are engineers!
    I've tested mics on a PSU and look for drop-out thresholds, and then I know for certain.
    Then I have left the mics on and monitored the voltage over time while recording the bars shown and know for certain, rather than guessing.

  • ercoerco Posts: 19,925

    An alkaline below 1.4 is good for flashlights or motors, but iffy in some electronics. Some AA-powered cameras which need lithium batteries, they only run for a few minutes on new alkalines. Hate 'em!

  • if you have to test a lot of batteries and don't trust the drop test, at least make a test jig consisting of a battery holder and a fixed connection to a voltmeter. If you need three hands to hold the battery and two voltmeter probes, you're wasting time. Personally, I prefer the drop test. It's fast and easy.

    -Phil

  • GenetixGenetix Posts: 1,515

    They don't make handheld battery testers anymore?

  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2021-04-30 11:58

    I use those cheap digital sliding jaw type where you clamp the battery between the jaws and it powers and displays the voltage. I had bought about 10 of them years ago and now whenever I want it there is bound to be one close by.

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