2pcs 1￵￵8￵6￵50 Rechar￵ge￵abl￵e Batter￵￵y,Using The 18650 Rechargeable Battery Charger (Does not Include The 18650 Battery Charger) (2pcs Button Top Batter￵￵y)

Good for battery powered travel fan…..replaced original batteries. I would guess fan will last through at least 2x sets of batteries.Always have to watch to see if a new fan with batteries is cheaper, but in this case, we have multiple fans so it’s worth it.

Great value, works great!

The (BATTERIES) are absolutely fantastic. The (CHARGER), on the other hand “”NEEDS TO BE LOOKED AT””. The (CHANGER) which came my batteries, is “”JUNK””. I put the batteries in the charger and plugged it into wall outlet. After 24 hours, the (LIGHT DID NOT) change to show (FULLY CHARGED). I install the batteries in my head lamp and plugged it into to my wall outlet. (5 HOURS LATER), my head lamp was working great. My rating for (4 STARS) is due to (FAULTY CHARGER). Batteries did charge up and worked great. I do recommend batteries as “SUPER FANTASTIC”.

Work great. So far are keeping charged.

I bought two of those with a holder (from a different seller) to power a small multiband radio that I carry with me while I am traveling. It needs a 7.5V power supply or five AA batteries (5 x 1.5 = 7.5V), which is inconvenient since they are normally sold in multiples of 4.I thought two of those 18650 batteries (2 x 3.7V = 7.4V) in a battery holder with the appropriate plug that can be attached to the power supply jack can be used as a backup power supply.Amazon lists those as 4000mA-hour batteries, whereas the fine print on the body of these batteries says 5000mA-hour. My radio consumes about 50mA at moderate volume, which would give me a battery life of 80 – 100 hours before they need recharging.When these 18650 batteries arrived, I put them in a charger I have, and in a couple of hours the green light indicated that they were fully charged. I measured the voltage in each of them and they were charged to 4.0V x 2 = 8.0V. (a little high for my radio, but not a big deal).After listening for about 10 – 15 hours (not even that) using the newly acquired and fully charged 18650 batteries, the sound started to get distorted, which showed that the batteries were close to their end of life. I removed the plug, and the sound came back to normal due to the AA internal batteries in the radio.I measured the voltage, and it was 2.9V x 2 = 5.8V, which means they were fully discharged. I was very disappointed since I was expecting at least 40 hours of operation assuming that their capacity would be at least 2000 mA-hours, regardless the 4000 or 5000 mA-hour as advertised.The next day I did a controlled charging of the 18650 batteries giving them a constant current of 100mA until the voltage reached 4.2V X 2 = 8.4V, which is the maximum voltage for this kind of lithium-ion batteries. I left the voltage unchanged afterwards and the current died down to negligible values showing full charge. It took all this about 8 hours to complete.Now my disappointment grew even bigger, this means that their charging capacity is 8 x 100 = 800mA -hour. The discharging capacity cannot be more than 85% of this, which is roughly 650mA hour. Really? Batteries advertised as 4000 or 5000mA-hour are in reality 650mA-hour ones.This item is completely misrepresented and a fraud to be sold anywhere, including Amazon.

Better battery then AAA for flashlights that can use 18650

The 18650 battery is one of the most common rechargeable battery types. In fact, some cars use battery packs consisting of hundreds of these type batteries. This particular battery seems to be from a non-big name source, but worked well for me. In some devices, this type of battery may be easy to replace, just like in a flashlight. But sometimes device manufacturers solder a small control chip and circuitry directly onto one of the battery contacts. That was the case with my device. So I carefully de-soldered the circuitry from the old battery, and carefully soldered it onto the new battery. But I used a high quality temperature controlled soldering station, with a narrow tip. The trick is to heat only the tiny area you are soldering, without heating up the battery. It requires quick precise work with a high quality soldering station. Don’t try this unless you have the right skills and equipment. Use eye protection. It can be extremely dangerous, even fatal, if the battery gets hot from soldering.

I bought 4 - two discharge within 30 minutes, the other two take hours, on the same lights. It's frustrating.