SHENMZ 4-Pack Battery for 3.7V 3600mAh Flat Top Battery, Rechargeable, 2 Bay USB Battery Charger for Flashlight, Camera, Small Fan, Sound Equipment.

These batteries compare favorably in performance to their "name-brand" counterparts from Imren, Samsung or other "big names"The batteries arrived enclosed in a pair of 2-unit plastic battery cases of decent quality. No issues with shipping or packaging.The Shenmz battery exterior is clearly labelled with brand, battery type, capacity rating and saftey/usage instructions. This compares favorably with even the big name brands which are often marked in such a way as to make it difficult to identify these things.Most importantly, the stated 3400 mAh capacity rating is honest! After opening the package, the first thing I did was to drop them into my charger, as I expected them to only be at half-charge or less "out of the box" - this is SOP for most types of rechargeable batteries, including these (storing/shipping at half charge extends shelf life and is safer). After charging, I put them into my device for a practical "real world" test - no issues here, they lasted nearly twice the time that my previous batteries did at that (end) point in their lifecycle. I then took the (now mostly discharged) batteries and put them in my charger and set up the charger to run a complete full charge-discharge-charge capacity test under 500 mA charge/discharge load. Upon completion of the test, the results indicated a capacity right at or above 3400 mAh. The lowest of the four tested at 3386 mAh, and the best at 3422 mAh. These results were a pleasant surprise - most new batteries I've tested tend to over-rate their capacity by 100-200 mAh, but these tested right at their rated capacity (within the margin of error for the tester). I re-ran this test a few weeks later after having put the batteries through at least 10 charge-discharge cycles of regular use, and the test results came out nearly the same - no appreciable loss of capacity noted after multiple use cycles.Bottom line: These batteries perform at least as well if not better than their "name brand" competition, and I would not hesitate to recommend them to anyone looking for a 18650-type high rate discharge battery set.

Looking at purely specs I thought this would be a great vape battery. On my Sigelei Humvee dual 18650 paired with geekvape Zeus tank running 55w with a pair of freshly charged set of batteries, the mod drops to 47w and immediately starts to drain the batteries.They do work fine as flashlight batteries or power source for robotic / dyi projects. Not for vaping.

Got these for my vape as an upgrade from the 3100ah battery I had that wouldnt last very long at all. These 3400ah batteries last way longer and provide enough power for fatter milky rips of the vape. And you get FOUR! You don't wanna sleep on this deal folks. Easily one of my best amazon purchases of all time and I shop on amazon a LOT.

Must plug into a usb plug, not included. Chargers don't last. Batteries are great.

charger takes 7 hours to charge fully

I've been using these for a year now in my led flashlight. I use that daily for extended periods, and only have to charge the battery in it once every two or three weeks. These batteries have held up very well, with no significant drop in charge when stored. They have the current to support that flashlight also.The charger sucks, but I have a better one that I normally use. I hang onto it for a spare, but it really is a poor charger.All four of the batteries, on the other hand, have been great and I'm buying more for new projects.

The batteries are good, but the charger is completely unusable. I didn't come into this with an expectation that it'd be stellar, but it's almost impossible to get it to recognize that a battery is in it, and then it can sit for hours and not charge a bit. If you don't already have a charger, buy one separately.

These the longest lasting batteries I've ever used in my mod. They last all day.