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How To Test a Battery Without a Multimeter

Everybody has batteries in many different kinds of devices and sometimes it’s useful to know if the batteries are good of bad. Of course the best way to test it is with a meter but not everybody has a multimeter and you don’t always have one handy. Here is a simple method to test any AA, AAA, C, D alkaline battery.

There is no official scientific explanation, except this one made by MagnumForce51:

“What I think is happening is that there is a transfer of mass between the anode and the cathode. The cathode is the negative terminal on a battery. (the flat bottom). In a fully charged battery, the mass is more uniform. But once discharged a majority of the mass from the anode is transferred to the cathode as a result of the chemical reactions that went on in the battery that allowed it to produce electricity.

So this alteration in the distribution of the mass within the battery had a noticeable effect on the bounce. I bet what is happening is that the cathode of the battery is heavier and thus more of the inertia of the battery is transferred into the table allowing more rebound (remember Newton’s laws of motion? For every reaction there equal reaction. Since the table is immobile most of the energy of the falling battery is transferred back into the battery with some being absorbed by the material of the table).

The mass of a fully charged battery however is either more uniform or closer to the top/edges and so not as much of the mass gets it’s energy transferred. The end result is the bottom of the battery absorbs more of the impact and thus results in the “thud” because the inertia had been absorbed by the cathode material then would have been if the battery was discharged. (cathode not as dense, so it can absorb more impact)

I honestly don’t think gas buildup would have any measurable effect on the bounce. These batteries are small. What ever amount of gas they produce is so small, it can’t alter the end result. It’s more to do with the change in mass of the cathode in relation to the anode”

6 Comments

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  • joribo

    yeees, but the spring effect seems to be true, and maybe this is a combination of gas pressure behind the lid and the deformed shape of the lid. Making the end of the battery to something like a soccer ball. I am not sure but dont have any better explanation.
    Here a link, a guy who has worked on regenerating alkaline cells and has explained their internal “secrets”.
    http://www2.ife.ee.ethz.ch/~rolfz/batak/
    I gave up the regenerating of normal alkaline cells due to the risk of leakage. But I still regenerate the special cells which are made for it
    http://www.accucell.de/pdf/OEM.pdf
    If someone is interested, I have written a report about my experiments with regenerating of alkaline cells, including schematics, can mail it (german, english version under work).

  • joribo

    I have worked a lot on regenerating alkaline batteries. Although the procedure itself is imho doubtful (the risk of leakage cancelles the benefit), there is a special effect which could be noticed.
    The old batteries and especially freshly regenerated old ones showed a slightly greater length due to the minus-lid deforming to a slight belly shape. In case of regenerated alkalines it is very probably the internal pressure. The slight double-curvature of the else straight flat minus lid might be the root cause of the bounce behaviour, which is mentioned in the above video.

    • Jim Keith

      Did you know that grinding the face of a hammer perfectly flat makes it about as effective as a ROCK in transferring energy?

  • Jim Keith

    After fooling around with a few batteries out of my ‘spent’ battery bag, I was amazed at the difference. If there is any life remaining, they do not bounce and if truly dead really BOUNCE –unfortunately, my camera gives up on the batteries when they drop to about 1.4V or so –not nearly discharged.

  • highlandham

    Testing 1.5 V alkaline batteries (AAA & AA)should imho be done under load of say 200mA .If under this level of load the voltage drops below 1 Volt i consider the battery as ¨spent¨ to be discarded

    For this purpose I have put a dc milliampere meter(measuring range unimportant ) with a scale of 0 -15 or 0 -150 in a cubical Twining tea tin
    Across the test connections I put an approx 1.5 / 0.2 = 7.5 Ohms wire resistor (scrapped from a heater element).
    Also across the test connections I have put a trimpot in series with the milliampere meter .
    With a fresh 1.5 V battery connected ,the meter is (with the trimpot ) adjusted to full scale deflection .
    Any battery tested should show under the load not less than 2/3 of full scale deflection ,meaning 1 Volt

    The trimpot resistance value depends on the meter´s current range .
    Example : for a meter range of say 0.5 mA the trimpot should be approx 4.7kOhm

    I have used this type of battery tester for the past 30 years.

    It is a simple KISS solution

    • KROKKENOSTER

      Okay the test

      Okay but the problem is to “test” batteries when the tester is not handy This is a dinky solution as you do not need an “expensive” tester for a lay person . Most uninformed know as much from electricity as a cat know of saffron and it scares them . If your hobby fine but to buy a multimeter just to test batteries is not on. Some places ask for a multimeter the price of several other new batteries and if you change batteries once every six months on your radio

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