Two identically packaged Zebralight 18650 3.6v - different output in charger?

[SockToy]

Apols if this is noob. Im puzzled. I have an XTAR VC2S here. Both batteries bought at the same time from ZL, one reaches 4.2v after charge, one 3.6 - almost like the regulator/protection circuits in the 4.2 arent doing their thing.

But Im a total battery noob. Am I missing something? Dont think its a setting on the charger; have tried swapping the bays and same result for same battery.

Cheers

Matt

 

[Hooked on Fenix]

4.2 volts is normal for a fully charged li-ion battery. 3.6 or 3.7 volts is what is written on the battery, but they charge to 4.2 volts. Does that help?

 

[SockToy]

Not really; the question is why, fully charged, one gets to 4.2 and the other 3.6

I wondered if the protection circuitry was regulating the output to 3.6 even at full charge or something, but then the question would be, why does it differ between them?

Thank you for taking the time to reply. I'm puzzled

 

[Owen]

-Batteries from the ZL site don't have protection circuits, so that's out.
-The charger got one to 4.2V, and you swapped bays, so that should eliminate the charger itself.
-That leaves the battery, or some kind of connectivity issue between it and the charger. I've never seen a partially charged(3.6V) battery refuse to take a charge.

What does the digital display on the VC2S show when you attempt to charge the battery?