The Nintendo Switch Joy-Con Battery Pack is currently on sale over at Amazon, dropping in half. It is now just $9.97, which is a pretty good price to add a battery pack to your Joy-Con, allowing you to play even longer on a single charge.
These battery packs for the Joy-Con clip onto your Joy-Cons and then use AA batteries to keep them charged up. These are really good for extended playing sessions, especially when you aren't playing the Switch as a handheld console. This is an official Nintendo battery pack, so you're not getting some third-party one that could stop working at any time. That's definitely not something that anyone would want to have happen here.
Typically, this battery pack will run about $21, but it has been as high as $35 sometimes. It also does not stay in stock for long, so if you are looking to get your hands on one of these, now is definitely the time to do just that. You are going to want to grab it before it goes out of stock again, especially at this price.
You can pick up the Nintendo Switch Joy-Con Battery Pack set from Amazon using the link below, for just $9.97.