Hi
I have had a few batteries from ebay sellers and most have been utter rubbish with most being well below the claimed capacity with one set which claimed to be 1700mAh tested out at 170mha.
Also watch out for low price genuine batteries as most of those are counterfeit and are mostly low cost, low capacity batteries printed to look like the genuine item.
Of all the one I tried I got the most out of the following Brands, DSTE and EXPro. but they even counterfeit those as well, which makes buying on eBay and Amazon a bit of Russian roulette.
If you can afford it buy the genuine ones from a known good supplier, if you cant afford it try looking for the brands above on eBay and try to limit you search to a supplier based in your own country, I got my good ones from UK based sellers.
Paul