Wiimote rechargeable batteries

So, after years of wanting to have a Wii since my childhood, i got myself the console a week ago! Im planning to get another controller so i can play wuth friends and all that stuff. But i was thinking about batteries.

I already had a pair of rechargeable batteries from my house that i use, but i am going to need another pair. So i found this rechargeable packs from internet that has some sort of usb dock for charging, it comes with 2 batteries and the prices is near the same as 2 AA rechargeable batteries. They sound so good to be true.

Are they really good? they last enougth? I would love some advice here

TLDR: Are the battery pack for the wiimote (the one with usb charging dock) good or not?