Weltool 16650 Protected Lithium Rechargeable Battery Build-in USB Port Adopt 2500mAh 3.7V Japanese UR16650ZTA core as Replacement for 2 CR123A

The Streamlight ProTac 2L-X and the regular batteries are very expensive. So I found myself only using it as little as possible because of the running cost. After buying this 6 months ago, I carry the Streamlight everywhere and use it all the time. This product has paid for itself many times already.The life if probably 80-90% of the Streamlight disposable batteries I was using. Do buy a backup though. As with all rechargeable batteries, it goes from just starting to dim to completely discharged with little warning.

This is a great option for replacing 2 CR123 batteries in certain devices. Need to make sure the input voltage in the device can work on lower than 6v. This battery is 3.7 volts, fits the Streamlight ProTac 2L perfectly, and works very well. Really liking the fact that I can use it all I want and not worry about purchasing more expensive CR123's all the time.

Great batteries. Just know they do not replace 2 123's in all lights. My older Streamlights will only take 123's specifically because these are ever so slightly wider.

It was easy to charge and seems to work well in my Surefire light. It is just slightly longer than two of the CR123's so the cap doesn't screw down quite as tight but works.

Dead on arrival and it didn't fit my streamlight tl-2-x it was too long. Sent it back

I ordered these as supplement to the Keeppower 16650's which are on backorder and not available. I use these batteries in a variety of night vision and thermal imaging devices. These Weltool batteries, while having the same electrical specs as the Keeppower's, are slightly longer and therefore are a very tight fit in all of my devices. While the devices power up and operate normally, I am concerned about compressing the springs in the device housings, and also the significant pressure I have to exert to screw the retaining lids on. Would be challenging to be in the middle of a field in pitch blackness fumbling around for what should be an easy 1-minute swap. Won't be buying them again.

Battery is actually 3mm longer than 2 CR123A batteries, making for an extremely tight fit. On a full charge it's pushing 4.18V. It won't work well in flashlights that have a 6V draw, for that you will need a pair of RCR123A 3V (extra emphasis on 3V, not 3.7V) batteries. However there are some flashlights out there that have a lower draw that this will work wonders for. This battery didn't work for my light, but I'm sure I'll find some use for it.

I bought it to replace the double CR123 batters in a 5.11 TPTL2 flash light. It fits perfectly and is working great. The battery was fully charged when it was received.