There are charging areas at all (except maybe AK, I haven't checked there) the parks.
MK - Space Mountain store - the back of the store has a wall dedicated to charging. There is a counter with a massive number of ports (wall ports, not USB, so be sure to bring the converter as well) as well as stools to sit at.
MK - Tangled bathroom area - between the two paths from Fantasyland to Liberty Square, there is a little area with tables and barrels. The barrels each have 2 ports, but they tend to fill up fast and are filled consistently, so I don't recommend trying here.
MK - Storybook Circus - There is a small rest area at the back of Storybook Circus that has some ports and benches. I haven't tried it to see how many there are, but that area tends to be very relaxed so if you are there it is something to check out.
MK - hub? - When they first reopened the hub earlier this year, the lamps all had outlets. Since they closed and redid it again, I'm not sure guests are able to access those ports anymore
EPCOT - D-zone (behind the exit for Club Cool) - It's just a hallway but it is inside, they recently added tables, and it is air conditioned
DHS - Jack Sparrow lounge - I haven't been there and it isn't always open. But it is a spot.
I'm sure there are more that I am missing. But those are what I have used.
But absolutely invest in a portable charger if you don't want to wait while it is charging