30v 18650 cell! About to explode??

jawnn

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a funny farm near Seattle
[FONT=Trebuchet MS, sans-serif]Itook apart an old battery pack I had for bicycle lights, it hadstoped working over the year that I was not able to ride my bicycle.So two good cells at 3.6volts and one that read 16volts! I put it onmy Imax B6 to discharge it but the device said too low of a voltage.When I read the voltage again and it had gone up to 30v!!!! andfinnaly down to 26v....is it about to explade with an internal short?Or is there a chemical brake down? [/FONT]


[FONT=Trebuchet MS, sans-serif]Ithink My I -max B6 is not working right. It is reading a cell thatshows 3.9 volts [acording to my hand held meter] as too "lowvoltage". Is there a kind of charger that will show amps of thebattery being charged?[/FONT]
 

WalkIntoTheLight

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I highly doubt your cell is really at 30v. It would have gone boom long before it reached anywhere close to that. I suspect your meter is wrong.
 

peter yetman

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There's no way the voltage could increase without engergy being put into the cell.
If your readings vary so much over a short period I would also suspect that your meter needs looking at. Does it need a new battery?
P
 

kpatz

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Jan 6, 2018
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Are you sure the meter was giving you volts? If the battery is completely dead it may have been giving you millivolts. The units should show on the display.

There's no way you'd get 30V from a lithium cell no matter what. It would have gone kaboom long before reaching that voltage.

I'd toss that cell in the recycle pile.
 

snakebite

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dayton oh
make sure you are not reading millivolts(mv).
also some really cheap meters read way high when their battery is weak.
it may not be weak enough to turn on the low battery indicator but its low enough to cause serious errors.
example is harbor freight freebies.
 

kpatz

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The meter is showing millivolts on the bad cell. You can see the units display change on the top right corner of the LCD from "m V" to "V" when you test the good (blue) battery. You can also tell because it's reading millivolts when the probes have no battery connected.

The bad cell is dead, near 0V. Recycle it.
 

jawnn

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Nov 26, 2008
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259
Location
a funny farm near Seattle
The meter is showing millivolts on the bad cell. You can see the units display change on the top right corner of the LCD from "m V" to "V" when you test the good (blue) battery. You can also tell because it's reading millivolts when the probes have no battery connected.

The bad cell is dead, near 0V. Recycle it.


thanks... that explains a lot. now if I can find the manuel for the meter I might under stand it better......
 
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