Yuntunele Battery for 18650 Rechargeable 3.7 Volt High Capacity Genuine18650 Flat Top Flashlight Battery for Headlamps, Doorbells, Handheld Fan.

I ordered the Yununele Y18650 batteries to power my digital camera gimble, and so far, they are doing that; although I have not run them down to exhaustion yet. I have no instrumentation for checking the seller’s assertions as to capacity, however I do appreciate prior reviewer’s insights in this regard. The seller does state that peak efficiency is achieved after 3 – 5 full charge cycles. I do have a voltage test though, and it confirms that the batteries are outputting the correct voltage. I have no way of knowing what their charge state was when I received them, but the initial charge took about 4-hours. On the other hand, as someone that has reviewed quite a few products from Chinese sellers, I’ve found that in the case of electronic or other specialty items where testing the seller’s assertions may take special tools and/or skills, they will exaggerate to the benefit of their profits. That said, Amazon has very consumer friendly return policies, so that can be no risk in trying newer products. In the case of the Yuntunele batteries, I will wait to pass judgment until I have discharged and recharged them 5 times, as the seller suggests. After that, I will have an empirical insight into their capacity, since I know how long the original batteries lasted, and can thus make a comparison. What I can say now is that they are working fine and, I like the purple color. I’ll rate them 5-stars for now because I have no reason not to, but will come back to this review after 5x recharges, or any other important insights come to light.

One works fine r a little while, the other does immediately.

They don’t recharge properly

These are 18650 batteries, but they do not have the protrusion on the positive side of the battery (this is why they're called "flat tops"). By being flat, they are shorter and may not work in your device. I have several flashlights, and these will only work in my red or green flashlights; they do not work in any of my white-light flashlights. This is not a rule, just my observation - your results may be different. The batteries do hold a charge well, and I can charge them in the same charger I use to charge the other style 18650s with the protruding positive post. If they will work in your device, then I recommend you get some.

I got two of these 18650 cells and tested them. They arrived half charged, which is expected as it save production costs and shipping/storing at 50% SOC helps improved longevity. Both looked identical but after charging up, only one managed to deliver anything close to the rated 2500 mAh (2540 @ 500mA). The other clocked in at a bit over 1700 mAh. I charged them both back up again and got the same result. Not really sure why, as neither shows any kind of damage or wear. Bad quality control maybe?

I have been using these for a while now without any issues. It took a while the first time to get these fully charged. However, these do work well. I was happy to see they at least did what was expected. I have reused them a few times to not find any issues going forward. This is worth the price value.

Got these to augment my portable flashlights that use this format of battery. Even though this is a flat ended battery, due to the way it fits in my flashlights (spring loaded) it works fine as a replacement. It seems to hold a charge pretty well, and will be a good insurance to have along when camping etc. where I might want to swap out a battery rather than recharge it while out in the back country. The pair came in a nice plastic box which will protect them as well as decrease the likelihood of them being able to short out in a backpack etc.

The “Yuntunele Y1865O Rechargeable Battery 3.7 Volt Battery 2500mAh Flat Top Flashlight Battery” charges well. I got these as backup batteries. My old batteries have been charged many times but are still going strong. If you are wondering what a 18650 battery is, it is much bigger than a simple AA battery and will not fit into a slot designed for AA batteries. I just mentioned this for those who might be wondering.