4 Pack 3.7 Volt Button Top Rechargeable Batteries and 18650 Battery Charger,Lithium Battery 4000mAh for Flashlights, Headlamps, Doorbells, RC Cars,Outdoor Garden Lights（Battery and Charger）

They charge fast but don't seem to last as long as others I have

Delivered quickly. Charged evenly. I believe they will be good batteries at a good price.

The 2nd from the left slot stopped working, (just like our old one). Other than that it works great!

Charges and works fine for a 2,200 mAh battery. Not an exaggerated current capacity which would also take proportionally much longer to recharge if the battery capacity were actually bigger by 1.5x or 2x.

Bought 12 of these SkyWolfEye 18650 3.7V 4000mAh cells, ASIN B0CM2WTMHT, because my wife was complaining our older cells would no longer run her headlight for any reasonable length of time.After a day or two of using these new ones, she said they were worse than her old cells! This annoyed me, so I decided to see just what was going on...Using her headlight, I quickly discovered our older 3000mAh cells DID last longer... almost 2x longer! This seemed odd to me so I decided to find out what was going on.I purchased a 1A and a 500mA load tester for 18650 cells... The 1A load is a fixed resistance load normalized for their rated current at 3.7V. The 500mA load is a constant current load.I charged all the cells using my MIBOXER chargers that I purchased over the last few years on Amazon... The cells were allowed to cool to room temperature overnight and then tested on the 1A load. The cells were recharged using the MIBOXER charger, again allowed to cool to room temperature overnight and then tested on the 500mA load.The results were shocking, to say the least!While I have results for all 12 cells in a spreadsheet, I'm just going to post the best, worst and average for each load...For a 1A load, the best cell delivered 1181mAh of power, the worst delivered 1132mAh and the average was 1151mAh.For a 500mA load, the best cell delivered 1291mAh of power, the worst delivered 1188mAh and the average was 1255mAh.Considering that the rated capacity of these cells is 4000mAh, this performance, less than 30% of advertised capacity, is simply unacceptable.They have been returned to Amazon.I've ordered several other brands and will be testing them as they arrive.Bonus:I found 7 of these SkyWolfEye cells that have been in use for about a year and only charged in my MIBOXER charger...Just for the fun of it, I tested them.At 500mA load, the best of older cells delivered 665mAh, the worst delivered 220mAh. With that kind of performance, I saw no point in testing them at 1A.The results are clear.Not only do these cells fail to meet their specifications when new, after a year or so of use, they have less than 1/7 to 1/10 of their rated capacity remaining.Junk. Do not buy.--

These Quality Of These Batteries Are Surprisingly Well Made. Definitely An Upgrade To My OEM Batteries. The Charger Is The Same Quality. Well Made, Not The China Specials Being Sold EVERYWHERE !

Charger works great and charged batteries fast.

Long battery life