The Nintendo Switch's included JoyCon Grip accessory recharge your JoyCon controllers--you'll have to shell out another $30 for that extra bit of convenience. This poses some problems for console-owners, and will lead to interrupted play in TV Mode--and here's why.
Nintendo's new Switch console has two different kinds of JoyCon Grip accessories: the stock JoyCon Grip that comes in the box with the Switch that doesn't recharge your JoyPads, and the JoyCon Charging Grip, a $30 peripheral that recharges the JoyCon Grips as you play. Eurogamer reports that the basic JoyCon Grip that comes with the Switch won't have an internal battery nor a USB Type-C port to recharge your JoyCons, and we've corroborated that information via the official Nintendo Switch Fact Sheet that I've included below.
The included base JoyCon Grip only combines the JoyCons into a single controller to facilitate TV Mode play--it does not recharge the individual controllers. Now the stock JoyCon Grip does indicate battery power life, but it has no internal battery to allow recharging.