30 types of 18650 , comparison site

Just came across this , the guy has done some real legwork comparing 18650 batteries ,and its worth a read , over 30 types compared !

Torchy the Battery Boy: 18650 Batteries / Chargers


also a worrying section regarding ultrafires
Torchy the Battery Boy: The Dangers of Ultrafire 18650 batteries



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Nice find ! thanks for sharing

Ultrafire batteries have a very bad reputations. For the most part you are getting salvaged batteries that have an unknown history. They toss a PCB on them and wrap them up as a new product. I would never purchase them or buy a product that has them bundled with them. It is a real crap shoot...some are good...some are very bad. If you have any be sure to keep an eye on them while they are charging.

I think this tester has done a much better job on 22 cells @ five different current levels.
It is also more consistent with testing that I have done on several of the cells I use.



18650 Test Info:

http://lygte-info.dk/info/Batteries18650-2011.html

LarryDFW

about 5-6 or so years ago I had an Li-ion RCR123A sized "ultrafire" do exactly what the name suggests. It KATOed on me and set fire to my charger. I'll never trust them again.

Well, you may also want to check the output voltage of your chargers. I bought one of those "universal" ones, put a li-ion 123A battery in it, and measured the voltage...


The damn charger was trying to charge my 123A to 9 volts! :wtf:

Had I not measured it and stopped it, the battery would have DEFINITELY exploded. No doubt about it. :|

I've already complained to the seller and I'm definitely concerned about other people who have bought the charger... :gun: :scowl:


I also measured the above Ultrafire 123A and its 3 other sisters internal resistances... I got anywhere from 300 milliohms to almost 1 whole ohm.

A tad ridiculous. The seller has offered to refund me half the purchase price of the batteries (of $8, so I'd get $4 back) I have yet to hear back from the seller of the charger.

I'd like there to be some way of getting bad products taken down. They're a definite safety hazard.

Le Quack : I also measured the above Ultrafire 123A and its 3 other sisters internal resistances... I got anywhere from 300 milliohms to almost 1 whole ohm.

Click to expand...

That is precisely the reason to stick with "brand name" 18650 cells.

Much better build quality.

LarryDFW