Because of the price 4 stars!

Shelf life:
I could first shoot about as many images with these batteries, as with the original Canon battery, even with flash.
Its preservation can now, however, after a bit. Have the camera just gelegendlich in use, this own now for about half a year, am with about 4000 photos, which is split in 3 batteries. I appreciate that the batteries still deliver about 80-85% of the original performance, which is quite OK for this price.

Use:
Thick minus point is the use of batteries, because now after this time, I have about each image Wait 5 seconds until I can ever shoot the next picture (So until the flash is charged). The original can I determined about 10 Images shoot (series of images) without the "Busy" is on display.

Normally, I would have given the product 2-3 stars, but because of the price, which is about 50% cheaper than the original, I forgive 4 stars.

So I would say, people who shoot from time to family photos or make recordings at the zoo, this product is able to grow without concerns, however, should allow photographers thereof fingers.