Summary: I bought these with a gift card i received for my birthday a few years ago. When i went in and bought them i was told by the employee that they weren't a very good product as they tend to lose their charge quick and may in a rare case ruin my wiimote, but i bought them anyways as they were the only rechargeable battery pack for the Wii at the time and i thought they were a pretty good deal.
Pros: rechargable battery
Cons: stopped holding a charge after a week, not worth buying
Summary: I personally had a bad experience with this product. When we bought it, it worked great for a week. We found it inconvenient to keep taking off the covers every time we wanted to charge the remotes, but that was nothing we couldn't deal with. After about a week, one of the charging slots stopped working. We were still okay with it, because even though we had two main wii players in the house, the one charging was enough for us.