Just wanted to give a heads up on a batch of batteries purchased from a Hong Kong dealer on eBay. They were purple and labeled 2800mAh.
First indication I had something was wrong was they felt very light in weight. I put them on a digital scale, and found they weighed 19 grams. 2000mAh AA's usually weigh 28 grams and up.
Charged up a set and put them in my GPS. Less than 2 hours later they were kaput. Put them through a few more cycles to break them in, and same result. My PN-40 usually goes 8-10 hours on a pair of NIMH batteries (my old ones are 2200-2600 mAh name brand cells).
Put them on my MAHA C777PLUS-II charger/analyzer. In repeated tests of several different sets of the batteries, all sets showed a capacity less than 700 mAh. This was using the standard MAHA charge cycle ('fast charge', I guess), and a discharge rate of about 350 mA/hour. Using the same test cycle, my old Tenergy and Nexcell AA batteries show capacities over 2000mAh.
These batteries weigh about the same as a NiMH AAA battery, and have about the came capacity, so the manufacturer has apparently cut corners and put an AA casing around an AAA battery, and fraudulently labeled them 2800mAh capacity. A new low in Chinese junk cells.
I've bought generic cells before off eBay, and while they often didn't come up to claimed capacity, they usually came close, and were useable and cheap. It looks like that no longer is a viable option - the manufacturers/dealers will just plain outright lie and sell intentionally mis-labeled cells that are not even true AA batteries.
Some photos of the bogus cells: