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testing numerous AA batteries sitting around?

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Bill Baxter

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Feb 19, 2016, 2:11:52 AM2/19/16
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Over the last several years, I've had projects come and go requiring
mostly the use of both alkaline and lithium AA batteries. As some of
the oldest batteries have ended up leaking, what's a good way to test
the remaining ones to see if they're worth keeping or not? I have no
idea of their ages, some of them could be a month while some several
years. I know I can use a DVM or analog voltmeter, but many times I've
tested this way and supposedly good batteries only lasted a few minutes
or several hours in a device and thought there might be a better way. I
just need to clear out all questionable AA's.... too many on the
shelves. Thanks.

Chris Jones

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Feb 19, 2016, 2:50:44 AM2/19/16
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Connect a load resistor across the battery and measure the voltage
across the resistor with the battery under load. Don't do it for too
long or it will make the battery go flat, obviously.

The appropriate load resistor depends on the size of battery. I would
suggest maybe 0.5 Ohm or 1 Ohm for an AA.

For an AA cell you could also achieve a similar measurement result using
an ammeter provided you know its characteristics (burden resistance and
lead resistance, any fuses that are likely to melt).




Cursitor Doom

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Feb 19, 2016, 3:27:52 AM2/19/16
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On Fri, 19 Feb 2016 18:50:39 +1100, Chris Jones wrote:

> Connect a load resistor across the battery and measure the voltage
> across the resistor with the battery under load. Don't do it for too
> long or it will make the battery go flat, obviously.
>
> The appropriate load resistor depends on the size of battery. I would
> suggest maybe 0.5 Ohm or 1 Ohm for an AA.
>
> For an AA cell you could also achieve a similar measurement result using
> an ammeter provided you know its characteristics (burden resistance and
> lead resistance, any fuses that are likely to melt).

You could also zip through them unloaded with a DVM and 'whitelist' any
that show 1.6V or so, then use the resistor method on the rest. That's
how I'd do it, anyway.

Look165

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Feb 19, 2016, 4:26:09 AM2/19/16
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The best way I know is the short-circuit current.

Try an amperemeter for test and measure the curent.

Don't last more than a fraction of second for this test.

If it is more than 1A, the cell is OK.

The open circuit voltage measurement is generally always OK before the
cell really dies.
This tests never give any information about the internal series
resistance which is the first symptom of a dying cell.

Bill Baxter a écrit :

MJC

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Feb 19, 2016, 4:48:00 AM2/19/16
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In article <na6f23$867$1...@dont-email.me>, bbaxte...@msn.com says...
I have a 1.25V 0.25A MES incandescent bulb. It fits in a simple holder
made of heavy galvanised wire wound into a spiral that the bulb screws
into, with an extension of caliper shape that connects to either AA or
AAA batteries.

The test takes 2 seconds per battery.

If the bulb lights strongly the battery is worth a second chance...

Mike.

Sjouke Burry

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Feb 19, 2016, 2:38:22 PM2/19/16
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For small batteries I test the short-circuit current.
New batteries are in the order of 2-10 amps,
old ones 0 to ~100 milliamps.
Very useful when you compare old- with new battery.
Dont try this on big ones!!!!!

Wayne Chirnside

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Feb 20, 2016, 7:13:59 PM2/20/16
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Or just buy a really cheap voltmeter from Harbor Freight.
Mine cost $6.00 and HAS a loaded battery test function with the milliamp
reading to be expected for a good battery right on the case.

I like them as cheap disposable meters but never use them on high voltage
other than the simplest tests and then with great caution as they
obviously aren't built with much or any real safety features.

Ralph Mowery

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Feb 20, 2016, 7:42:19 PM2/20/16
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"Wayne Chirnside" <ma...@faux.com> wrote in message
news:5j7yy.30304$ZY2....@fx22.iad...
>> Or just buy a really cheap voltmeter from Harbor Freight.
> Mine cost $6.00 and HAS a loaded battery test function with the milliamp
> reading to be expected for a good battery right on the case.
>
> I like them as cheap disposable meters but never use them on high voltage
> other than the simplest tests and then with great caution as they
> obviously aren't built with much or any real safety features.

I did not think anyone bought those meters as they are usually 'free'. I
have 3 of them now. Not too sure how well they will hold up, but I did
check them with my Fluke meter and they seem to be accurate enough for
general testing. They do have one adjustment inside,but I did not see the
need to try and get them any closer.

As with you , I don't think I would use them on anything other than some low
voltage stuff. Maybe on the 240 volt around the house, but not too sure
about that. I know I would not use them on the 480 volt 3 phase stuff at
work that had about 600 amp fuses in it.


Phil Allison

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Feb 20, 2016, 9:16:09 PM2/20/16
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** Does not look that bad:

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_23332.jpg

It lacks low AC volt scales and the plugs are not fully shrouded.

The transistor tester socket is a known hazard and I cannot see if battery access requires the use of a tool, much safer if it does.

The battery test function is almost useless, 4mA load on a AAA or larger cell tell you nothing - particularly if it is rechargeable.



... Phil












Ralph Mowery

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Feb 20, 2016, 10:59:33 PM2/20/16
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"Phil Allison" <palli...@gmail.com> wrote in message
news:bf4fba29-ef9e-4347...@googlegroups.com...
> Ralph Mowery wrote:
>>
>>

> ** Does not look that bad:
>
> http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_23332.jpg
>
> It lacks low AC volt scales and the plugs are not fully shrouded.
>
> The transistor tester socket is a known hazard and I cannot see if battery
> access requires the use of a tool, much safer if it does.
>
> The battery test function is almost useless, 4mA load on a AAA or larger
> cell tell you nothing - particularly if it is rechargeable.
>
>
The plugs are fully enclosed once they are plugged into the meter. To get
to the battery you have to remove 2 small screws and the whole back comes
off the meter.
Yea, 4 ma might load a battery if it is almost dead, but it is not much of a
load to tell about the condition of the batteries.
Not sure how long they will last, but for free, you can get lots of them if
you do buy anything at HF. I have some around the house just to keep from
going and getting my good meters if I want a quick check on some light bulbs
or something like that. Just as I keep a few other tools around different
parts of the house and in the cars.


Ron D.

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Feb 21, 2016, 2:36:02 AM2/21/16
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I use the HF meters because it's easy. For other batteries like the CR2032 and LR44 I've written the new values on the meter.

Now I also date AA batteries when they are installed and write MT (empty) when they are dead. Then stored and recycled under the battery category. Multiple coin cells generally stay in a tiny 3" x 4" zip lock when re-cycled.

Phil Allison

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Feb 21, 2016, 8:02:40 PM2/21/16
to
Ralph Mowery wrote:
>
>
> > ** Does not look that bad:
> >
> > http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_23332.jpg
> >
> > It lacks low AC volt scales and the plugs are not fully shrouded.
> >
> > The transistor tester socket is a known hazard and I cannot see if battery
> > access requires the use of a tool, much safer if it does.
> >
> > The battery test function is almost useless, 4mA load on a AAA or larger
> > cell tell you nothing - particularly if it is rechargeable.
> >
> >
> The plugs are fully enclosed once they are plugged into the meter.
>

** Well yeah, but the shock hazard occurs when handling a plug - trying to put into the meter - when the tip end is attached to a source of high voltage.


> To get
> to the battery you have to remove 2 small screws and the whole back comes
> off the meter.
>

** Excellent - batteries are shock hazards if they can become exposed by mere finger pressure or a bump.

The other common DMM hazard is having a non-fused high amps range - if connected across a source of high energy, the leads may explode. Such sources include car batteries and high current AC supplies.



.... Phil


Bob Engelhardt

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Feb 22, 2016, 10:11:53 AM2/22/16
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On 2/21/2016 8:02 PM, Phil Allison wrote:
> Ralph Mowery wrote:
>> The plugs are fully enclosed once they are plugged into the meter.

> ** Well yeah, but the shock hazard occurs when handling a plug - trying to put into the meter - when the tip end is attached to a source of high voltage.

I can't imagine myself attaching a lead to a high voltage source before
it is attached to a meter. Or switching the meter connection after it's
attached. Maybe it's something one starts doing when the plugs are
fully enclosed.

Bob

Phil Allison

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Feb 22, 2016, 7:34:57 PM2/22/16
to
Bob Engelhardt wrote:

>
> >> The plugs are fully enclosed once they are plugged into the meter.
>
> > ** Well yeah, but the shock hazard occurs when handling a plug - trying to put into the meter - when the tip end is attached to a source of high voltage.
>
> I can't imagine myself attaching a lead to a high voltage source before
> it is attached to a meter. Or switching the meter connection after it's
> attached.


** But you can imagine the plug coming out of the meter unintentionally, then being replaced while "hot" or touching ground/chassis and causing a massive short.


> Maybe it's something one starts doing when the plugs are fully enclosed.
>

** Shrouded plugs make it safe to leave probes attached to a high voltage or high current source.

Been a standard feature of any decent DMM for decades now.


.... Phil




jf...@my-deja.com

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Feb 22, 2016, 9:13:30 PM2/22/16
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On Monday, February 22, 2016 at 4:34:57 PM UTC-8, Phil Allison wrote:
> ** But you can imagine the plug coming out of the meter unintentionally, then
> being replaced while "hot" or touching ground/chassis and causing a massive
> short.
>
> .... Phil
Based on a sample of one, that is extremely unlikely. The shroud on the plug fits very tightly in the case, and there is additional friction from the banana plug. Even if you snagged the meter, you will probably pull the probes out ot the CUT before the plugs come out of the meter.

BTW, the one significant flaw in my HF meter is that it does not have a low-battery indicator. The calibration seems very good with fresh batteries, but gets very bad when the batteries are weak.

Phil Allison

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Feb 23, 2016, 12:33:32 AM2/23/16
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f...@my-deja.com wrote:

>
> > ** But you can imagine the plug coming out of the meter unintentionally,
> > then being replaced while "hot" or touching ground/chassis and causing a
> > massive short.
> >
> >
>
>
> Based on a sample of one, that is extremely unlikely.
>

** Pal - you need a bigger sample.

> The shroud on the plug fits very tightly in the case,
> and there is additional friction from the banana plug.
>

** Fit tightness becomes irrelevant when the plug is shrouded.

Hate to think of someone's life or eyesight depending on it.


> Even if you snagged the meter, you will probably pull the probes
> out ot the CUT before the plugs come out of the meter.

** It is important to believe in " Murphy's Law" when discussing safety.

It can happen, so sooner or later - it will.



.... Phil




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