Thank you to the person who said to put a piece of aluminum foil between the two batteries to make contact, I thought I had waited 26 euros until I saw the comment, I also purchased those for a flashlight , and this fixed the problem !

The truth is that while I wrote the details I wanted in the search and it seemed to keep them, it doesn't.

Just received, the positive pole does not protrude at all from the battery body, possibly resulting in not making contact with the next battery in line and needing to put some washers between them to make contact. It seems to be for devices that only accept one battery. I will try it and let you know.

They lose one star because the terminals do not protrude and if you put 2+ batteries one on top of the other, they do not make contact. So if your device uses 2+ batteries with a connection one on top of the other, they won't work.

I bought 2 for a flashlight and even though they charge, they don't work, probably because they don't make good contact with each other. Edit 2, this was final, the positive pole is pressed inside the batteries and doesn't make good contact with each other. I don't know if it was just my batch, but I came up with a solution, I put a piece of copper between the batteries to make good contact and the flashlight worked normally. You can also use aluminum foil or something else that has good conductivity like a metal ring. I discharged them and recharged them moderately, they reached 5100 to 5200 mAh, everything is fine

I have had the 1st EFEST 26650 for a year now and I just got a second one. I am generally satisfied with its performance and duration (in the D4SV2 flashlight).

These specific batteries have a pulse rating of 40A and a continuous rating of 15A. If you want 45A/18A, ask the store before placing your order.

Quite powerful compared to other no-name brands, in terms of battery life, I haven't needed to charge it yet to know its duration

I placed it in a high-performance 1400 lumen flashlight and the autonomy it provides is clearly great, and I would say that the brightness has also improved. Also, during charging, which is done through the flashlight and lasts about 4 hours, depending of course on the size of the charger, once it is fully charged, it automatically stops charging, so the battery is not at risk of overcharging. I don't know if this last feature is a merit of the flashlight or the battery.

Very powerful battery, I made a mistake by not buying two and now I will have to pay for shipping again.... However, I will definitely buy it again.

AEGIS, ZEUS

I have it for 3-4 days so I don't have a spherical opinion.
As a first impression, it's very good. With heavy use on an e-cigarette, it lasted me 1-30 days.
It takes a while to charge, but it's logical with so many mAh.
Be careful because in some models it may not fit, like in my Aegis. The battery cover doesn't completely close for 1-2 millimeters.
I will come back in 6 months when I will have an opinion on performance and battery life.

Very good battery,
but it has an issue with the size, it is 66 in height so there is a problem with the closure in Mod H.T and it is quite heavy

Very reliable battery, I have it for about 7 months and it's a beast. Super performance and relatively fast charging with a 1A charger.

If you forget them on the charger for 2-3 hours (What a bad and rare thing), they break as well.. instantly. This happened on the first charge, they stayed 3 hours longer. I tried each battery one by one and they were all dead!

Initially, I was hesitant to buy it because I had no experience with Efest. I read a good review and bought it.

http://lygte-info.dk/review/batteries2012/Efest%20IMR26650%205000mAh%20(Purple)%202017%20UK.html

I have had it for about a month and it is excellent. I use it for an electronic cigarette. Its measured capacity in a month is 5280 mAh (more than the specifications). I charge it at 0.5A at night.

I will update the review after six months of use (I forgot).

After 2 years of use (day by day): Its performance started to decline at 18 months, but 25 months later, I still use them normally. I measured the capacity and it is at 4584mAh. I am impressed.