I wrote an uncomplimentary review of the two battery packs I received via the Amazon "market place" route. That review is not now viewable and I wonder why??. The two battery packs that arrived were both suspicious and warrantied scrutiny. The batteries showed attributes that did not match comparison with the original genuine Canon battery I had. The batteries did not work at all. The batteries could not be charged at all. These batteries were a waste of money. Then add cost of electricity trying to charge them. Plus waste of my time and a little effort packaging them to return them to a vendor who after a bit of prompting eventually did refund the initial costs plus the return postage only.
To prove the conclusions I arrived at I subsequently purchased a single battery pack from a well known retail outlet with absolutely none of the difficulties I had encountered previously. This latter battery pack's attributes relating to packaging and detail text matched exactly the genuine Canon product.