Not rechargeable. Looks like it takes 3 AA batteries, which are included with the purchase.
My wife loves doing all the little scavenger hunts they do at
Disneyland (Easter eggs, pumpkins, etc.) so I knew this would be right up her alley. She had a blast doing it. My daughter took a turn at New Orleans Square since she's a saxophone player who loves jazz and I did the one in Galaxy's Edge since I'm a big Star Wars fan. We did it all in one night.
I find the Disneyland App a little overwhelming so maybe there's a logical place where it's located that I can't readily find, but if you use the search function and type in 'Key to Disneyland' you'll get the full description of the event and the ability to find the stations on a map, which is helpful. Even though I knew where the portals were from the description, we passed the one up in Galaxy's Edge so it was helpful to see our little locator icon in relation to the portal.
One note is that we missed getting into Toontown before it closed down for the fireworks so we milled around for awhile until it reopened. When we were going back over to do that station, we found that there was one available right outside of the Disneyland Railroad station, which was available while Toontown was closed. Not sure if they only bring it out during the closure but wish we had known about it instead of waiting around to do the one near Roger Rabbit's Car Toon Spin.
I'm not sure if it was mentioned earlier in the thread but make sure the key is "on" before inserting it into the keyhole. It will still activate the bubbles and music without doing so but your key won't have the icon light up otherwise. Found that out by accident when the key auto shutdown after too long of inactivity.
I hope that they are able to keep the bubble solution restocked at all of the stations throughout the event and that the activations continue to work as well. There's more than one at each station so its fun to watch others and see what animations or sounds they get too.
We didn't do it for the pin but it was cute how it was available in the key after the final portal at the front of the park. We got the Pooh honeypot, which was probably our least favorite design, but it was still cute.
I know a lot of people are surprised at the high price. Is it worth it? Not sure everyone would think so but it was an enjoyable little thing. The key with all the sounds and lights is pretty cool. We had fun with it for sure!