Universal Smart 2 Slots 18650 Battery Charger Set,4 Pack 3400 mah Rechargeable Button Top Batteries Battery for LED Flashlight Headlamp, Remote Controls,etc.

The charger works great and the batteries work great as well. Last longer than the original one

So far it works as it should: light ups showing it’s charging and when it’s done. Will update accordingly…

Appears to charge the batteries that it comes with without issue.

I smoke a vape I bought these for my vape and not only was their power output absolutely miserable but the batteries from positive to negative end to end were of different sizes not by much but enough to wear two out of the four didn't fit inside anything that uses those batteries that I own do not buy these absolute horrible product

Head flashlight, works Great

Fast delivery. I was expecting two batteries and it came with four. Excellent

The batteries have a rated capacity of 3400 mAh. I tested one of them in a flashlight that takes a single 18650 li-ion battery, leaving the light on until it started to dim. The battery was discharged after approximately 2 hours. For comparison, I repeated the test with another brand of 18650 li-ion battery, lower-rated at 2600 mAh. --That battery was discharged after approximately 3 hours.Not all 18650 li-ion batteries are created equal. This was a rough test, but the lower rated battery clearly outperformed the higher rated, "3400 mAh" battery. I don't know the actual capacity of these new batteries, but assuming they're all of uniform quality, they appear to be lower quality cells. They may be OK for casual use, but I wouldn't use them in situations where reliability is critical.The included charger works, but it doesn't include a power adapter. In order to charge the batteries, you need to connect the "charger" to a 5 volt output adapter, such as those commonly used to charge cell phones or tablets.The paper-thin plastic sleeve has already cracked and peeled off the button end of one battery, and the little donut ring around the tip has come off, leaving the metal fully exposed. I could attempt to glue it back in place, but I'll probably just toss the battery.

I collect 18650 and similar batteries for making power banks using reusable battery cases so I have emergency chargers handy for my phone, flashlights, Walkie-Talkies, tire inflating pumps and other gear. I try to use recycled/salvaged cells when I can for the environment, but for batteries I know I can truly depend on a new, fresh set now and then is always a worthy investment. These are a good deal because you get the set of four matching batteries, two plastic storage cases to keep them in, a charger for them and the charger's USB/USB-C cable all together. The charger itself is very basic, it has a red light for charging status that turns green when finished, no progress bar or anything to give you an estimate of the remaining time needed, but compared to my other chargers I already own it works about as fast as average at getting these filled, and it didn't heat up at all even after charging a battery back from drained to full over 3 and a half hours. I like the spring-tension retaining holders that slide down to allow these and also larger or smaller 3.7V lithium batteries of different types, too, that makes it nice to have around versus a charger that only does the 18650 batteries.The batteries themselves are of great quality, and did not ever get hot while charging or using, a very good sign. I fully drained and then recharged them first thing before even beginning to evaluate them, and after a recharge to prime them up they tested very well. In my high-intensity camping flashlight on its highest "searchlight" setting these lasted an average 2 hours and forty minutes before going out, which is about just right compared to other batteries I own of similar capacity as these. The voltage at discharge was 2.86V, and after recharging these came off of the charger at 4.15V, so a normal range for this battery type. I am pleased that even at peak they stay just a little bit shy of a full 4.2V, which 18650s theoretically reach at top. The difference between an old "500 cycles" battery and new ones that go well past or even more than double that is often found just from limiting that voltage peak by 0.1V or 0.2V, and it's something I look for now when trying to guess if a battery will really last long-term for me or not.After some discharge and recharge cycles to really evaluate these I was more than pleased with the capacity, reliability, and quality of them and their charger. The plastic storage boxes are just great, too- you can never have too many spare battery cases! Altogether this is a great set, I give it a full 5-stars!!