They charge from empty to 3400mAh. They could be better, but I have bought worse ones. They come without a case

I don't have anything to say about lifespan for now, but the mAh that my Nitecore charger showed me from empty was 3800+ on both that I bought, so I believe their capacity is true (it never reaches exactly the nominal)

They were used for the repair of a DEWALT electric drill battery. They are suitable for such use as they withstand a lot of current and can power tools for heavy and demanding use.

they have a smaller capacity, about ~ 3600mah
such capacity can also be found in 18650.
since I bought it for a flashlight to have light all night, I am thinking of returning it but I don't know yet.

Okay, the batteries are fine. After some uses, the performance will decrease and at some point, we will throw them away as well. I use them in a handheld flashlight and they last longer than a flashlight with a 18500mha battery. So they definitely have the capacity they claim.

I bought 4 batteries. One was already faulty. The others capacity diminished fasted after being used a few times.

I can't understand why I ordered a Samsung and received this battery.. Does it mention anywhere the model and brand? However, the capacity and dimensions are correct... I used to also buy from China like this

The batteries are great!!

I bought them for my vape.

I recommend you to buy these batteries and don't look for any other...

Unfortunately, I returned them because simply they do not fit in an electronic cigarette... they have a longer body and are a little thicker.

It is the 21700 battery that most vapers use. Very reliable and withstands a lot of abuse.

Excellent, as long as you receive the authentic ones. Some stores have other brands with Samsung wrap.

I bought it for my Geek Vape and I was impressed with its performance. In fact, I bought 2 and the first one lasted for 2 whole years without ever needing to charge it. Highly recommended for those looking for a reliable and high-quality battery.

It's so terrible that I bought Moricel and they are just as terrible!
I don't know how some people give them good ratings when both of them are terrible and a waste of money.
They don't go over 2500mAh in charging. And now ALL of them are giving me an error on the charger.
My charger is brand new, the XTAR X2.

Just bought it. I plugged it in to charge and it had 3.6V. Seems like low storage voltage to me. I will come back with further comments. I will use it on the astrolux ft02s flashlight

I bought them for a single battery mod electronic cigarette, but they are all over the place in terms of capacity!!! I bought 4 pieces and NONE of the 4 reaches the promised 4000mAh. The best one reaches 3800mAh and the worst one reaches 3200mAh. Other batteries are much much better. Stay away from these...

So I have had these batteries for about a month. They have gone through at least 15 charges and discharges. Definitely, at least mine do not have the capacity that they claim, and both are around 3250-3450. That's why I give them 3 stars, otherwise they provide very good currents, they don't struggle at all, and they don't get hot either. With the capacity that mine have and with the mod that I have, the vaporesso Target 100, they last me 2 days, maybe 2 and a half, heavily vaping at 30 to 35 watts, with a loose MTL draw.

Their capacity is about 60% of the old ones I have had for a year. It's a shame for their price. Scroutz sent me 2 new batteries that were okay

The best on the market along with the molicel p42a in 21700. Just make sure they are genuine because there are many fakes out there!!! Be careful where you buy from!

The best battery I have tried, 40 Amps. This is very important, I have bought so many batteries. Only these I use, good performance. Good power and even when it's half, it still maintains its performance, it is reliable

I bought two to alternate them in a mod. One lasts 1 to 1.5 days and the other barely lasts a day. I need to measure them to see their capacity. I don't see a significant difference from the Sony 18650 batteries.

Very good 21700 batteries. At 85W that I vape, they give me around 450 to 500 puffs. About one day. I also have the Molicel as a second pair, equally comparative. I highly recommend them

Very good battery, I had it for almost 4 years where I replaced it with the same one again because its performance started to decline. In a review I had seen in 2019, it was voted battery of the year!

The capacity of them is 4 Ah. The dimensions are slightly above the indicated 21x70 mm approximately +1 mm in diameter and +0.5 mm in height.

I bought one and it turned out to be bigger, it fits with difficulty in the groove or the drag X. It also seems longer in length besides the thickness. An old one I had was okay, but the one they sent me is terrible

The capacity of it is a big flaw. It says 4000, but the one I got is only 3200. The equivalent 21700 that I have, the 30t, has almost the same performance. The difference in puffs is only 75, vaping at 24 watts. The 30t has 450 puffs, while the 40t has 525. Other than that, it has good currents until the last puff.

The XTAR VC4 2860-2900mAh battery doesn't last me a whole day like the competitive Eleaf AVB 21700 4000mAh battery (in the XTAR 3620-3700mAh). What can I say...

They are durable, the packaging is as it was after 2 months of use, but the truth is that I take care of them as well.
The only thing that bothered me is that they do not have a capacity of 4000mAh as promised... it is about 3500mAh... it lasts me 1 day of vaping with low watts from 15 to 20 watts.
I charge them with an external charger and not directly from the device.

With the xtar vc4 charger, it reaches 3400 mah. It holds for almost 4 days with 20 watts on the cigarette, so I am satisfied.

I bought this battery for use in an electronic cigarette, after reading various online reviews. I had also bought the 30t, which although it has clearly better performance than a 18650, it cannot be compared to the 40t. The battery simply doesn't exist!!! It easily lasts over a day with moderate use at 55w