Bests & Worsts Reviews from Amazon

I just finished testing one set of those AmazonBasics AA NiMH Pre-Charged Rechargeable Batteries, using my old La Crosse BC-900 Charger/Analyzer. Here are my findings: - Right out of the box, their average remaining charge is 1946mAh. The spread is very small, ranging from 1933 to 1959mAh. Note that the date code on those cells says 'MAR2011', so they probably left factory just two months ago. Still, those numbers are really impressive. - After just one recharge/discharge cycle (done at 700/350mA), the average capacity improved to 2217mAh. That is about 11% higher than the rated capacity of '2000mAh'. Again the spread is small, varying from 2200 to 2250mAh. Those numbers remain unchanged in subsequent recharge/discharge cycles. Just for comparison, the NEW Sanyo eneloop AA cells are also rated for 2000mAh typical, but the average capacity I measured is around 2130mAh, or 'only' 6% higher than rated. On the other hand, Sanyo claims the second-generation eneloop cells can be recharged up to 1500 cycles, whereas GP and AmazonBaisc NiMH batteries are rated for 'only' 1000 cycles. In real life, most people will probably never notice the difference. In summary, all three brands I mentioned above (Sanyo, GP and AmazonBasics) are excellent products. They all live up to the claim of "pre-charged and ready to use right out of the pack", and offer even higher capacities than rated. So just go by which brand is on sale, and you can't go wrong. [Aside] Most battery makers are touting their products as 'Advanced', 'Platinum', 'Ultra', and so on. Why oh why does Amazon simply call those superior batteries 'AmazonBasics'? If this is 'Basic', I can't wait to test the 'AmazonPrime' batteries! [Aside#2] Those AmazonBasics Pre-charged NiMH batteries are in black, which (to me) makes them look like disposable alkaline cells. On the other hand, the AmazonBasics Alkaline Batteries are in white, which makes them look like rechargeable cells. I really wish the color scheme were the other way around. [*Update on Apr 14, 2012*] Long term self-discharge data of AmazonBasics batteries were disappointing, so I have to downgrade my rating from 5 to 4 stars. I have tested one pair each of thos AA cells after 3, 4 and 8 months of storage. The average remaining charge measured were 82.3%, 79.4% and 67.6% respectively. That means they have already failed the claim of "maintains 80% of capacity after 1 year". If the present linear trend (-3% per month) continues, I expect them to retain only 55% of original charge after one year. In contrast, my previous test data with Sanyo eneloop and GP Recyko+ showed that they can retain at least 80% after 12 months. New bottom line: For most applications, those AmazonBasics cells are good enough. But for mission-critical applications, I have to recommend Sanyo eneloop instead. [Update on May 18, 2013] I have tested the AmazonBasics AA NiMH Charger, but cannot recommend it for recharging those AmazonBasics batteries. See my review on it for details: http://www.amazon.com/review/R35I4BN9IMHV58/ [Update on Oct 25, 2013] There is a new version of AmazonBasics Pre-Charged Rechargeable Batteries in white wrappers. Both versions are advertised as 'pre-charged' and have the same capacity ratings. However, the white version is made in Japan and appears to be rebranded 2nd-gen Sanyo eneloop. The black version is made in China by some unknown manufacturer, and its charge-retention rate is not as good as that of the Sanyo eneloop. Obviously the white version is a better deal.