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Battery giving out mV??

jakeGT

jakeGT

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Just got some cheapo ultrafire 3.6v 16340 batterys from batteryjunction

One of them is saying 28mV on my dmm???

IS this a bad battery or what? On my smart charger it says its fully charged?
 





Also, these are protected cells. Might that have something to do with these readings? Or is the battery fried? I just don't see why my charger is saying it is fully charged.

Heres the link

http://www.batteryjunction.com/uf16340.html


IF anyone has any thoughts on this, it is very appreciated

SHNIT! Sorry didnt mean to double post. I thought i was editing the last one, sorry :(
 
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Well if you're really actualy only measuring <1 Volt, then this battery is dead.
Does it power anything the other battery manages to power?
 
Well, I haven't tried powering anything with it.

I'm measuring it on my DMM with the battery load test, at 6v. the other battery is fine, it says 4.12v.

This other one goes up to 40mV and then if I hold the leads on there, it will slowly decrease all the way to 12mV and lower, the longer I hold
 
20614a2f.jpg


heres my dmm.

All other batteries are still reading fine, and I just switched the batteries IN my dmm.
 
it's dead, it's deceased, it's expired and has gone to meet its maker.
This.... is an ex-battery.

(Forgive me, survivors of the monty python gang)
 
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It was brand new to. Will be contacting battery junction for sure. Thanks for the input anselm

It's okay, it was only $4 but still. You don't ship me a dead freaking battery. It was still in the plastic sealed 2 pack.
 
Hey I have the same DMM!

However, it looks like you DMM is hooked up wrong. Your connecting it to the 10A connection. It should be connected black to COM and red to right.
 
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well, it works either way, you just use the opposite leads for + and -
 
yeah, actually the black one belongs ALWYAS in COM, and the red probe in the socket
on the right for every situation, except for the sole purpose of measuring
currents larger than 200mA.

The reason your setup still does work, is because COM and 10A are basically shorted together
internally.:na:
 
Lol, the batteries are probably fine.

When you hook a protected battery up directly to a DMM, current starts to flow, and is essentially unobstructed, which to a protection circuit can look like a short. Then the protection cell kills the flow.

Try taking a resistor, whatever you have handy (higher the better) and add it in series with the DMM. (so like positive terminal to DMM, DMM to resistor, resistor to negative terminal)

I bet you'll get a reading (won't be accurate, but won't show as if it's dead)

I've encountered this with protected cells before.
 
Hmmm, that might not have been the correct technical explanation for WHY, but it's still something I've run into... now I'm really curious though, because I've only noticed this myself with protected cells. It has to be related to the protection circuit - that would just be too large of a coincidence otherwise... ?
 
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