XTAR4150mWh (2500mAh) 1.5V AA Rechargeable aa Batteries: Longevity Safety Efficiency (8pcs 1.5V AA 4150mWh)

I've been using rechargeable batteries for decades, going all the way back to the days of the dumb charger and NiCd cells. I simply refuse to purchase throwaway batteries not only because of the environmental benefit of rechargeable cells, I have had my fair share of things ruined by alkaleak cells.I have several very finicky devices, mainly security devices and Friedrich wireless thermostats that simply do not play nice with my trusted Eneloop batteries. I purchased two, eight packs of these XTAR LiOn AA cells to see how they would behave in my troublesome devices. So far, they work perfectly.I have conducted several detailed load tests on these cells, ranging from a 0.2A to a 0.95A sustained, constant current discharge test to measure capacity. While none of the cells make it to 100% of the advertised capacity at a discharge current of 0.95A, they all performed very respectfully under the current load, delivering a sustained output of 1.5V for over 100 (0.95A) and 400 (0.2A) minutes respectfully.I have not been able to duplicate the reports that the cells get hot when in use, but they do get warm under a sustained heavy draw. I measured a battery temperature of 38C during the 0.95A test. Keep in mind that the cell undergoing the test was not inside an enclosed flashlight or similar enclosed space, so the temperature that the cell could reach in an enclosed environment may be significantly higher than when testing on the CBA.As to longevity, and whether these cells will reach the advertised number of cycles, that's hard to say given the length of time that I have had the cells in operation.My verdict, based on my experience and testing is that these cells appear to be of high quality, and they deliver as advertised.Putting the batteries to the torture test utilizing a West Mountain Radio Computerized Battery Analyzer, all of the cells exhibit a relatively flat discharge curve, with the loaded voltage staying between 1.5 and 1.45V right up to the point that they switch down to 1.2V before the cell is completely flat. The cell tested at 0.95A gave NO indication of stepping down to 1.2V, it simply shut off. If you are relying on a low battery signal to be displayed on some device that draws a heavy load, I suspect you will never see the warning before the cell shuts down. This is repeatable, in testing five cells at 0.95A not one cell gave any indication of dropping the output voltage to 1.2V before shutting down. However, at the lower current of 0.2A, the cell does drop its output for a significant amount of time to 1.2V which should be more than sufficient to trigger a low battery indication on most devices.All of the cells exhibit significant radio frequency interference when used in a portable radio rending the audio unintelligent. When used in my alarm sensors, or my Friedrich wireless thermostats they perform flawlessly.Will I replace all my trusted Eneloop cells with these batteries, in a word, no. Do they have a place in the modern electronic world, absolutely.I intend to take one cell and put it through a torture test of continuously charging and discharging the cell to see if I can get anywhere near the advertised cycle capacity and will update this review then.

These work GREAT, and they tell you when they are about to die (the old ones dont). CRAZY LONG life in clocks, keyboards and things that need a true 1.5v. REALLY good in my pepper grinder, lasts for MONTHS, and REALLY good on my e- toothbrush ((I charge them like 4x/yr)

I did a discharge test and all batteries exceeded the stated capacity and retained voltage for most of it dropping only towards the end of the cycle.

I can't really use these. They overheat in about a minute flat in a blacklight flashlight. 0/10, would not buy overpriced overheaters againUpdate: I noticed one of the 4 batteries had pealing ends and what looked like a minor leak. Horrible quality control.

I love these batteries! I’ve been using 16 of them, so far, in two power hungry Amazon Echo Wall Clocks and a couple of Roku Video Players. They’ve been working excellently. They outlast their alkaline AA counterparts and best of all, I don’t have to have a AA battery subscription anymore!I don’t know if AAAs will do as well, but I just might have to buy a set and try.

Does not work in my Schlage smartlock tray. The positive side nipple is smaller than a standard alkaline battery and does not engage the contacts correctly in the Schlage lock (why I bought them). Really not sure why the positive nipple is undersized, but note that for your application. If it is because of the LED light, I would recommend to remove that in order to make the battery a standard size as that is a much more important "feature" in my opinion.A smart design, but it doesn't work for my application so I had to return it.

First let me say that I had no problems with these batteries. They work well in my applications, which include a motor drive (fairly high instantaneous load). Compared to my set of Kratax 3500mWh AA's they work about the same. Comparing weight, the Kratax are about 1g heavier (10.5g vs. 9.5g).I bought these while they were on sale. So the question is are they worth it now at ~$46 for 8. From my experience... no. I saw no appreciable real-world difference. YMMV. At $36 for 8, maybe ok. I would like to see the lab test data compared to others such as Kratax.Bottom line is: I am happy with the product, but would not buy again at the current price point. I did not see a 16% increase in life cycle, and would have expected them to weigh more than the Kratax 3500mWh batteries.Lifecycle test is an automatic open and close kitchen garbage can, using 6 AA 1.5 volt AA cells. Both XTAR and Kratax AA cells used after 3 charge and discharge cycles. Both lasted almost exactly 7 days.For reference AA Alkaline last about 9 days. Did not try AA Lithium single use... Expensive and no point.

It's the first rechargeable I've found that works with my Blink doorbell and doesn't die in 2 days! Dump the energizers and get these.