How to test an alkaline 1.5V AA battery?
davejames
Posts: 4,045
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
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.
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
LOL, but the ANSI standard drop test wasn't really spec'd for modern alkalines and electronics
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
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
I just test with a meter. It’s it perfect but good enough for us. Never tried the drop test.
Considered as follows (Energiser)
< 1.3V 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.
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
They don't make handheld battery testers anymore?
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.
