Tacoboy, they are great if you want a 1/2 to 1/10th of listed capacity, low A output (not enough A to get maximum output out of many lights), very few to extremely reduced recharge cycle (many I’ve seen do not last 10-100 recharges whereas good quality batteries last 500+ recharges), possibly completely fake (some are not batteries but have a capacitor inside and are falsely labeled) and possibly exploding (almost all documented explosions are from these random cheap types) battery.
I ordered 16 Samsung batteries (great price, convex top) from Banggood 32 days ago, still waiting on the order to arrive.
Laptop packs use flattops and I’m looking to buy button tops.
(I’ve already bought 28 Samsung 26A laptop pull batteries, before ordering from Banggood)
Why did you even bother to ask? :Sp
Boredom.
only *fires that I would use are Trustfires, provided you can be sure of their authenticity. Been using them since there were no other decent choices. I would not buy any liIons on ebay, chances are you will end up with fakes.
My Trustfire 18650 3000mAh are being delivered later today.
Theres just some things its not worth risk or unknowns to save a couple bucks on… li ion is definitely one IMO.
just dont hold the light in your mouth like the guy in the hospital bed shot above.holding a pipe bomb is bad enough!
I would never do something as dangerous as holding a flashlight in my mouth or anywhere near my face, I usually just hold the flashlight tucked in the front of my pants.
If you already have some Sanyo flat tops then add a drop of solder to as many as you need. It works and is easy to do.
About xxxFires...there was a review some months back where someone purchased several. The old genuine ones were ok but the subsequent ones were found not only to be less than stated capacity but also USED/RECYCLED cells.
Now before you or anybody states that laptop pulls are used batteries...consider that these individual xxxFires may have been discharged below their allowed capacity and you cannot determine what that is because not only will you not know the origin but also the manufacture. Known laptop pulls do not get the abuse of individual batteries.
You need to start reading about Li-ion cells and their construction just for safety. This should give you an understanding of what happens. Forget about having the light in your mouth. If a battery pops or vents when you are in close proximity it will release a gas that WILL PERMANENTLY harm your lungs instantaneously, and anybody else in close outdoor proximity or in the same room.
Honestly speaking...nobody really needs dozens or hundreds of batteries. Do I have many - yes. Do I look for deals - yes. Do I get penny wise and pound foolish - hell no!!!! When brand new quality cells with protection can be purchased for just over $4 why bother with what many are telling you are unsafe.
All Ultrafire batteries are craps & extremely unsafe save money for other reputed batteries!
as somebody already stated, 18sixfifty sells sanyo blue top laptop pulls for $1 a piece. They are much better batteries. Each one is tested. yes they are originally flat tops but he will also solder buttons on for you. I’ve bought several from him and they are honestly the best bang for your buck. He’s a standup guy and sells a great product for a great price. I’m willing to bet you can put ANY of your current crapfire batteries up against the Sanyo’s he is selling and the Sanyo’s will win.
one of my “4000” mah batteries tested for 1481 mah @ 1A. another one can’t finish the test.
Maybe it’s just so powerful, you will just have to be patient. I had a similar problem with a GTL 10000ma. So powerful it blew up the testing equipment. So the fire brigade said. Lost a good shed that day. 
Marc.