Any way to recharge the JoyCons while in the JoyCon Grip?

My SO has been playing Breath of the Wild all day, but now the Joycons are low in battery. She wants to still play on the TV, but as of now, the only way to charge the Joycons seems to be when they are embedded in the Switch screen.

So is there any way to charge the Joycons without them being in the Switch screen? Any way to charge them while they are in the grip?

An answer can be found here stating that:

If the Joy-Con are removed from the Switch, they can be charged with the Charging Grip. That also has a USB-C connection, and plugging the cable into the Grip, which is sold separately for $29.99, will charge those controllers up.

Additional information is also found there.

Please Notice: I do not own a nintendo switch, I only beleive that the above states the answer :) .

Confirmation:

Cad97 confirms that this is the answer but that

the charging grip does not have a battery and thus must be plugged in to charge the JoyCon

Full comment is found below. :D