Tenergy Propel Lithium Battery 40 Pack

Background: I bought a 40 Pack of these Tenergy 123 batteries about 1 year ago (in 2010). Have used them almost exclusively in Surefire and Streamlight 2 cell flashlights, as well as in my bedside pistol's green laser/flashlight. The one cell pistol laser/light has seen a lot of use over a period of about 6 months and is still on the original battery. Due to my use of around 16-20 batteries so far in my flashlights, I am confident enough that these batteries are either the same or close enough to brand-name CR 123 batteries that I am comfortable enough waiting another month or two before proactively changing out my weapon light's battery (reference "About ALL Lithuim Batteries" below:). I use my high-powered flashlights excessively when hunting, camping, construction, and walking along high traffic roadways. I have 10 years experience as an engineer in the Armed Forces. Five Star for These reasons: -Batteries are either the same or close enough to brand-name batteries that I treat them accordingly and literally trust my safety and security to them. I am not equipped to do so, but it would be interesting to use the appropriate equipment to test the voltage drop and amp hours on these batteries as compared to name brand batteries. I would not be surprised if these Tenergy batteries were slightly lower in mAh, but fully expect them to be close if not identical to name-brand batteries. I have used 12 or so Surefire brand batteries in the same lights I have now, as well as a few other brand names. Tenergy is the only "off-brand" product I have tried. -This particular brand is extremely economically priced, and the packaging of the ones I ordered a year ago were wrapped up in plastic as 4 rows of 10, with each 10 batteries being shrink wrapped in 1 linear row, side by side, where it is possible, with minimal care, to take 1 battery out at a time allowing you to store the rest safely. -Have not done much research on the subject, but these batteries do have the "protection circuit" built in, as do all major brand-name batteries. This is not one of those "child" safety locks like you see on butane lighters these days, nor is it like the various kinds of safety locks you see on modern American firearms, rendering the product less effective or altogether ineffective, but is in fact a much desired if not required component in CR123 batteries that will eliminate user or device error, as well as any very rare battery defect. I have never had this particular feature "go off" on any of my batteries, nor do I expect it to ever do so. Not knowing much, I would view it as either a fuse or circuit breaker built into the battery. Due to the nature of the items I use these batteries in, I did some minimal looking into of the protection feature of these batteries, as I did not want my battery to determine if my devices would or would not work. Knowing what little I know now about this feature, I would be hesitant to use any CR123 battery without this capability. -If trying to impress your friends (or yourself), these batteries' wrappers/labels do not look cheap or like knock offs, and do not send the message to any patriotic friends that you have bought a foreign label (I know good ol' Duracell manufactures many of their own AA batteries in China now days). They are as astheticly pleasing as most name-brand batteries, and much better looking than some brands, and, even with my rough handling, the labels hold up just as good as any, and look like fresh, new, shiny, high quality batteries that are well and carefully made. About ALL Lithium Batteries: -All Lithium batteries (as well as NiMH and NiCd rechargables) will give consistent performance from the time they are brand new/fully charged until they are discharged. This fact gives almost no indication that this type of battery (regardless of brand, amp hours, rating, manufacturer specifications, etc.) is close to being depleted. These afore mentioned batteries will suddenly die when their time is up, versus an alkaline battery which will slowly lower in voltage as it is depleted. This can be demonstrated, or, if not armed with this fact, learned through experience, by noting that, in a flashlight, a lithium powered light will suddenly not have any more power and suddenly die when the battery is depleted and the voltage plummets straight towards zero, versus an alkaline powered light in which, as the battery depletes, the light will start to dim until the point it is no longer effective. A mechanical alkaline powered device might demonstrate this effect by slowing down as battery power is used (such as in some of your childhood toys), while a lithium powered mechanical device (can't think of any at the moment) would suddenly run out of power. This effect can be further explained by looking at graphs of a battery's voltage decay over a period of time. A lithium battery's voltage will remain near constant, whereas an alkaline battery's voltage will drop. -Lithium batteries can cause problems if not properly stored. If the two terminals are connected without a resistive load (short circuited) such as could happen if held in a pocket full of change or stored loosely on a shelf that also houses loose nuts and bolts, they will discharge quickly and with a great amount of heat. I personally go so far as to not expose dead batteries to these situations. As such, "creative" storage solutions, such as duct taping them to a forearm, throwing them loosely in a glovebox, etc. should either be avoided or carefully considered. -Lithiums must be disposed of properly due to their toxicity. I do not know the details, but look at the Periodic Table of Elements and watch some You Tube about that column of element's reaction with water. -They have a VERY long shelf life and can be stored, by this user's definition of the word, indefinitely. More specifically, most have a shelf life of about 10 years or so.