First, the batteries themselves are fine. They provide a good amount of charge before needing a swap. Having 2 batteries in the kit makes it easy to plug-n-play when one dies. That being said... The power source for the charging station is USB-based, similar to phones (and seemingly every electronic device these days), however it only comes with the USB cord, no power adapter. My guess is that you're supposed to plug it into one of the existing USB ports on the Xbox One. Isn't an issue really, unless.... .... you play with multiple controllers. The kit is nice, but it's really best used for just one controller. Since you'd lose the pack altogether if it dies and have to replace it with the one charged battery, it's not a good idea to use if you have more than one person playing consistently. Which means you'd be losing TWO USB ports on the Xbox One if you used more than one controller often (which really makes not having a USB-based power adapter all-the-more inconvenient). Even still, I'm only using this for my kid's Xbox who usually plays solo, so it's not an really an issue in my house (plus, we had an extra USB power adapter laying around, luckily). But I wouldn't use this for the main Xbox since we tend to play more group/family games on that one (no pun intended).