I do not highly recommend 3rd party batteries, at least for serious works, not gd idea. I tried some time, first they dun hold charge as well and self-drain faster. Have to charge them every now and then to maintain their full capacity, while the original Canon battery hardly loss any noticeable charge after weeks (this hints at the quality of cells used)
3rd party batt lifespan is shorter bcos i am sure they dun use good quality cells, what kind of hi-quality Li-Ion can I expect for "$25"??? I can barely get a normal 4xAA Enelope Ni-MH type battery at $20! They dun seem to last as last as they stated ie i dun think 1400mAh is not really 1400mAh, like perhaps 1/2 to 3/4.
Battery cell quality and fabrication differs, just like Enelope or any other normal rechargeable batteries are different. Canon original batteries work very well, everyone who have Canon DSLR will of cos know that.
I have 1-2 Canon BP512 that are still doing well after 3-4 years of usage! They are very worth it longterm to say the least. Well of cos even if the 3rd party battery is bad, it is only $25, use and throw also can la, thats also a tempting idea for cheap multiple backups in the bag.
However Yi fen qian yi fen huo.
