BestShopBuyNow.com

Great inexpensive backup, not a replacement for the real battery.
I took this battery with me on a trip to Thailand last month.
I only used it a few times because I recharged the main battery every night.
This is great for an emergency backup battery which is what I used it for when I was out somewhere without access to power on extended use of the HF200.
This battery does NOT allow the camera to see how much power is left, (it only comes with two prongs instead of the four necessary to communicate with the camera, so it only supplies power, NOT information) so you use this battery only as a backup as you will not be able to tell how much juice is left in it.
But for who's complaining, at least I didn't have to fork over the exorbitant amount of money for a second Canon battery!
Definitely worth the for the emergency extra battery in the field.
I highly recommend it.

No problems, but not compatible with OEM battery
This replacement battery worked fine with my Canon HF100 camcorder. Lasts about an hour (as advertised). However, be aware that the included charger cannot charge the Canon OEM battery that came with the camera, which I had hoped it would. Also, the battery will not charge when in the camera and the AC-DC cord is plugged in. Basically, the only way to charge it is with its included adapter. The adapter is very compact and easy for traveling, so it is not that big a deal, but something to be aware of. Also, this replacement battery does not have the "smart" technology so there is no readout on the camera LCD screen showing how much battery life is left. Overall, you can't beat the price for a backup battery, just be aware of the limitations.

Not a perfect replacement ---but
Well we have a choice, pay one fifth the price of an OEM Canon battery and live with a bit of guessing at the remaining charge or pay full price for a Canon 100 percent compatible battery. I have been using both this and Canon batteries on my VIXIA HFS S100 and having good success. Of course Canon has to make life a bit more complex when you turn on the camcorder by telling you that you don't have a compatible battery making you say ok, you would think they are selling ink. Of course charging will require you to remove the battery from the camcorder. You will probably do good with this battery.