"overcurrent protection" !?

[MrMcChicken]

Hi all, I found out something really interesting.
I have got two 18650 batteries from ultrafire. There is written on them " overcurrent protected ". So I measured the Amps of the batteries and they nearly blow up my multimeter.

I measured them in the 10A setting, and got 20A out! I don't want do damage the batteries or my multimeter, so I measured them for just a second or two. They get warm after a short time too.
Thats a lot of power, but it seems not to be " overcurrent protected " or did I misunderstood something?

 

[PersonGuyDude]

Welcome to chinese manufacturing

 

[Hiemal]

Doesn't surprise me.

Don't take anything Ultrafire posts or says about their specifications seriously....The only thing that may be true about it is the voltage and other than that, nope.

They're usually old batteries re-wrapped and branded as Ultrafire or "___"fire batteries.

Only try to use true name brand batteries like Panasonic, Sanyo, Samsung, LG, etc

 

[MrMcChicken]

Thanks. Yeah, I really wondered about this .. so that batteries don't seem to be such a great quality, but I hadn't any promlems with them yet ^^. I'm using them with my red build.
Do you think the part about the mA/h is true?

 

[AnthoT]

Thanks. Yeah, I really wondered about this .. so that batteries don't seem to be such a great quality, but I hadn't any promlems with them yet ^^. I'm using them with my red build.
Do you think the part about the mA/h is true?

Take it's actuall capacity and your getting at most 1/2 that if not 1/4.... I've gotten a "ultrafire 3000mA" measured at 354.... Then I threw it out

 

[MrMcChicken]

Oh ... thats really less .. I hope my aren't as worse as yours ^^

 

[Hiemal]

Yeah, I dislike their batteries.

I trust generics more than I do ultrafire ones, because at least generics are brand new and not rewrapped old batteries.

I measured the internal resistances of my 16340 ultrafires, and got anywhere from 400 milliohms to 1 ohm. Little ridiculous.

 

[jasonck08]

That doesn't seem right, most of the lower quality batteries do have working overcurrent protection, but its set very low, like 2-3A, because they only use one mosfet.

Makes me wonder if the battery even has a working protection circuit or if its a fake circuit?