Probably the best 3rd party battery available.
I am very wary of buying non-OEM battery packs. The mAH ratings are always inflated and they perform terribly. These seem to work as well as the OEM brand without the high price tag. Other cells tend to weigh less and don't last as long. There is no way a battery can have almost twice the capacity, weigh less, but last nowhere near as long. These are as close to OEM as you can get.
Rechargeable Battery does it's job for Canon Rebel EOS T3i
This battery had no issues when I plugged it into my CANON REBEL EOS T3i. charges great and lasts a long time like I expected. I don't do tons of flash photography I prefer using natural light and light I can play with in my environment. I may purchase more in the future, currently have 2 batteries after 3 years with my camera living off of one.
Either defective or crappy product. I charged this battery. Got a green light, fully charged. Took one picture to test it. . Turned camera off. A week later I turned camera on and the battery was dead. I was unable to use my camera for what I needed it.