I have only one positive thing about this product - It arrived in a timely manner, otherwise I am not satisfied and plan on tossing the product in the trash.
First off the battery packs don't fit properly into my Wii Controllers - these controllers are the legitimate Nintendo product not a spin off to save money and they have no damage to them. The pack is the "correct" size but they do not latch on correctly and stick out. Because they don't lock in the battery won't work unless I tape it down.
Another issue with this product is that even when plugged in, the charger only works when the system is running. So if I am wanting to play my system, I need an extra set of controllers while the other ones are charging.
Fortunately, I didn't shell out a lot of cash for this product because it won't be doing me any good.