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Possessed battery?

Vonder

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I've never seen this behavior before, so I thought I'd share it and see if anyone else has seen it too.

I have a Kodak-branded PX28LBPK 6 Volt Lithium Battery and was using it recently in a Canon AE-1 Program. The camera acted kinda weird - seems like the meter worked only occasionally, but I was thinking maybe the camera's electronics were dying and didn't give it TOO much thought. The film came out ok, so I re-used the battery when I took my Contax RTS II out for a stroll this weekend. More weirdness. The camera meter would come on but immediately went out. Again, innocent me, figured well, this one may be dying too. But when I got home I checked the battery with a voltmeter.

Now the weirdness starts.

The meter was jumping all over the place, 8.6v, 5.3v, 10v. I was baffled. Meter was fine, leads plugged in properly... so I tested a nearby 1.5V battery and it read a solid 1.55v. Then I went back to the weird battery and it had calmed down too, a steady 6.5v with no flucuations. I put it back in the Contax and sure enough, the meter stayed on when I used it.

It's clear to me the battery was causing issues with both cameras. I have never seen a battery act this way.

Have you?
 
I would not use it in any camera if the voltage jumps up like that. However, my limited knowledge of batteries tells me that is impossible, unless the battery itself has some electronics in it.
 

Yes, it's most likely a bad internal connection in the battery itself.
 
I have used Duracell PX28L Lithium batteries an all four of my Canon New F1's and my Canon A1 for about 25 years and have never had any problem with any of them.
 
Within a long-cylindrical Lithium battery there are metallic contats, there also is a PTC-resistor.

Thus two possible causes for a broken circuit, bad hardly for a 10V reading when nominal voltage is 6V.
 
AgX said:
Within a long-cylindrical Lithium battery there are metallic contats, there also is a PTC-resistor.

Thus two possible causes for a broken circuit, bad hardly for a 10V reading when nominal voltage is 6V.
Click to expand...

Just to be clear, I meant the voltage numbers just to indicate it was wildly fluctuating, but they might not be 100% accurate. The meter never stopped, it kept going from one reading to the next.
 
Have you checked the outer contacts of the Lithium battery? Ground or polished them, where you put you metering electrodes?

Yielding correct reading on another battery does not exclude that something was wrong in your metering with that Lithium one.

(But again, that neither should result in indicated voltage above 6V.)
 
Some batteries are comprised of multiple cells; often stacked button cells. This is usually the case with the PX28 silver-oxide battery but I don't know if also the case with your lithium battery. But, when you have stacked cells, you may have an issue with just 1 or 2 of the cells. Or with the connection between cells.
 
The battery is suffering from intermittent connections. It is time to put the battery to rest and invest in a new battery.
 
Possessed. If you do get the evil spirits out of your battery but it happens again,

*****WARNING*****

Does that mean it's been repossessed??????????
 
Was the battery-checker analog?

I don't thing you can trust a digital voltmeter to check battery voltages.
 
Digital voltmeters are best for checking digital batteries. [I cannot believe that I posted this!]
 
Bill Burk said:
Was the battery-checker analog?

I don't thing you can trust a digital voltmeter to check battery voltages.
Click to expand...

Why not?

To my understanding digital voltmeters are even more apt as they typically have higher internal resistance and thus drain less and thus give more correct readings.

(For evaluating the useful state of a battery to the contrary a certain drain (equivalent to the real use) should be employed. That is why there are voltmeters as well as battery checkers.)
 
Last edited by a moderator:
AgX, are you walking around with one leg longer than the other*?





*Hint: He is pulling your leg.
 
A battery is best tested, under natural load, within the circuit it will be used in....if at all possible.
 
Well, yes, it is a digital multimeter. It's hard to find a reasonably-priced analog meter. I do recall that our standard voltmeter when I was an electronics technician in the Navy was analog, but that was because it was the 1980's and digital stuff was very expensive.

Thanks for all the replies, and yes,I have retired the battery. I wonder if there are rechargeable ones...
 
Bill Burk said:
Was the battery-checker analog?

I don't thing you can trust a digital voltmeter to check battery voltages.
Click to expand...

Yes you can, open circuit voltage is open circuit voltage. However, a multimeter of any sort is not a battery tester (which loads the cell or battery under test - a multimeter is specifically designed to load what it's connected to as little as possible).
Both of my digital multimeters will "hunt" when faced with an intermittent or varying input on DC and it's not uncommon for them to flash a reading that's impossible due to the circuit just not possessing that many volts. I have a Fluke and an autoranging Sperry, the Sperry in particular does this. My go-to meter is still a Simpson 260, though the digitals are nice for their nigh infinite input resistance.
 
Silly wabbit, just excorcise it. Have you tried cleaning the contacts with Holy Water??
 
As E. von Hoegh and others have noted, a digital multimeter is not ideal for checking batteries. I too have been a fan of the classic Simpson 260 for 60+ years, but often use cheap digital meters for convenience. Another powerful tool for analyzing strange problems is an oscilloscope.
 

Yes indeedy!

In the mid 80s, I was repairing home electronics. Sony, in their Trinitrons, was enamored of switching power supplies - which servicemen hated. I used a scope to trouble shoot them it made the job a real piece of cake.
 

Very interesting. But I just treid in vain to replicate your results with my handheld digital multimeter from the 80s (not autoranging).
 
Open switch voltage is just that. NO LOAD. If you have a marginal battery it can and often will read it's nominal voltage.
When a load is applied, even just a few ma it can drop below the required operating V.
 
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