Found a few threads on this same topic from many years back but none of them arrived at any tangible conclusion other than “it seems to work just fine”
Official Panasonic documentation puts this battery at a max continuous discharge of 4.2A~
However, using the 2C rule, theoretically a 3400mah cell should be able to handle 6.8A
I have been using it in a flashlight that pulls 6-7a and it works just fine.
So what’s getting lost in translation here? Is PANASONIC sandbagging the stats just to play it safe? My NCR is equipped with PCB, and that obviously isn’t kicking in above 4.2A, so I’m confused about exactly whats going on here.
Welcome to BLF.
You should trust the manufacturer’s data sheet and assume that they have done extensive testing on their products, which is a reasonable assumption for Panasonic.
While the cell may be able to deliver more amps it will probably get hotter and degrade (much) more quickly.
Never heard of anything called the 2C rule before. I don’t think that’s a thing.
I can’t find a datasheet that says maximum continuous discharge is 4.2A for that cell. At any rate, max CDR isnt maximum possible, bridge the terminals with a piece of copper and you can get >100A for a second, it’s just a recommendation for cycle life, retention of performance characteristics, safety, etc.
The protection circuit is built and installed by a third party. The current that the protection circuit steps in, if it does at all, is not at all related to the maximum continuous discharge of the cell.
[quote=“Paul, post:1, topic:220793, username:pdrew12”]
I have been using it in a flashlight that pulls 6-7a and it works just fine.
[/quote] For how long and what light?
The only datasheet I have seen for NCR18650B is pretty uninformative. It does not say the max discharge current but shows a discharge graph with a plot at 2C.
NCR18650B is a low current cell and the voltage gets pulled down quite a bit at 2C. The cell may get too hot (>60C) at 2C or greater continuous discharge currents.
NCR18650GA is a also high capacity cell which is rated for higher discharge current. It will run cooler at a given discharge current.
Vapcell N40 is a newer generation of cell which is rated for 4Ah and may sustain a 10A discharge.
