Keeppower Protected 16650 Li-ion Battery P1621U USB Rechargeable 3.6V 2100mAh 7.56Wh Flashlight Battery Included with a 2-in-1 Charging Cable (2 Pack)

I am using these as a rechargeable replacement for 2x cr123 batteries in a flashlight. It fits in my light and the cap threads on securely and engages the waterproof gasket, but it is tight.*If you are putting this in a dual cr123 device with tight tolerances, it will not fit!This style of battery seems to be longer due to the USB charging feature. If it fits, then it's a really great feature to have. If it doesn't fit, you will be unhappy.Also, bear in mind the voltage of a single 16650 is slightly lower than dual cr123's. Most flashlights should tolerate this (the light may or may not be slightly less bright), but some devices could have issues.

It's pretty simple - either you trust your batteries or you don't. I stumbled upon Keeppower originally from CPF and BLF and some of the flashlight manufacturers themselves recommend Keeppower if you want to buy 16650 or 18650 sized lithium batteries from them. In fairness to all other brands... I don't think I've ever had a single-cell lithium-ion battery go bad on me, so it could be that batteries (at least those of Japanese-sourced cells) are mostly similar in terms of quality. Even so, I will gladly keep buying Keeppower batteries as long as they're not grossly more expensive than their competitors.

Product does job just fine. However, it is not in spec to work in arisaka lights. This battery is slightly longer than most 16650s, such as the 2500mah option from keeppower. Arisaka recommends the 2500mah option (p1665j)

I purchased these batteries specifically to put in my Streamlight TLR RM2 Weapon Light which uses 2 CR123A batteries. The Item Description specifically states "Replacement for CR123A Batteries". This is NOT Accurate. The Keeppower 16650 battery is too long, and by quite a bit. I can't even properly screw down the light cap. While I'm pretty sure, had they fit, they would have worked well. I'm not sure if these batteries have worked in any other application requiring 2 CR123A batterie, but, for me this is a dead end. sending them back. The search continues...

I have been able to use my IR lights for many hours on a single charge and do away with the single charge style I had before.

I was hoping these would help to solve a problem I was having with an electronic device that is known to chew through batteries. The package arrived undamaged. During my initial charge of the batteries using the supplied USB C dual cable, only one of the batteries would charge. The other battery initially would show red that it was charging but then it turned blue. I then tried a couple of different charging cable and none of them seemed to work. I can not recommend these as only one of the two will charge which leaves me wondering how long the other one will hold up.

The products working great.