I have seen a great deal of good reviews on SterlingTek batteries so when I decided to buy more batteries they seemed a no-brainer. However, I always question reviews of new gear that hasn't been through the mill and now I have been vindicated. Two years ago I purchased two SterlingTek batteries for my Rebel, which my daughter took to college last year for photography classes. She complained that the batteries would not hold a charge. I assumed she wasn't doing something right.
Not long after I bought the batteries for the Rebel, I bought two SterlingTek BP-511A style batteries for my 40D. They worked great until I went to use them a month ago on a trip. Neither would take a charge! Luckily the original Canon battery that came new with the 40D still worked fine and held a charge.
I don't use my gear all the time but I did expect the batteries to last as long as the old Canon brand battery. Perhaps not using them shortened the life but then why is the even older Canon battery still chugging along?
I guess I will pony up the cash to get a real McCoy next time.