I bought 2 sets of these RC123 for testing out in my Arlo cameras. The standard Lithium batteries (Panasonic & Energizer) lasted about 2 weeks in heavy camera operation, with Klarus 16340, I'm getting just about the same usable life so these will pay off less than 3 charges, or about 1-1/2 month. One thing to remember is to have a second set charged ready to go or have to wait roughly an hour +/- to get a fully charged set of batteries.

My old Photography lighting meter hadn't seen the light of day for almost 10 years...
It hadn't worked because I couldn't find the replacement battery that it came with when I purchased it 12 years ago.

One quick search on Battery Junction, one quick order, shipped and delivered and NOW, I have one working light meter... success!

Thanks Battery Junction!

I have a LOT of flashlights. Most use 18650 batteries, but some have the option for CR123 or, in the case of some compact models, require them. I've tried both disposable and rechargeable batteries in these lights, and frankly, given how often I use these lights and the difference in capacity, I prefer the disposables. You can get 4 disposable Panasonic CR123s, each with over twice the capacity of these (1550mAh), for the price of just one of these.

I suppose if you have a light that you use constantly it might be more economical to use these rechargeables than to keep buying the Panasonics, but I just think these burn out too fast. For example if you're a security guard on a night shift and you want to use rechargeables, I suggest you bring spares, while a disposable could last the whole night. That said, these particular batteries hold a charge as long as any other RCR123A I've tried, and have held up so far with at least 10 charges each.

Comes in a nice plastic case. The battery itself is one of the top performers in this size. Real money saver. Buy several and keep charged for instant replacement on must have ready equipment.

So glad I decided to purchase rechargeable batteries for my security system!