I always bring the battery charger with me into the park and recharge whenever I stop for a meal. I also try to turn off the power any time I am going to be sitting for more than a couple of minutes, for example seeing a show or parade. I have trained my family members to keep an eagle eye out for outlets to use in the quick service restaurants. In table service, I ask the host or hostess where I can plug in and charge. If you need to stay in your chair to get to the table, figure out where to get plugged in, drive to the table, slide into a chair and have someone else in your party take the chair back and get it plugged in.
There are also many places to plug in and recharge around the parks, especially EPCOT. The food court in the Land has outlets all along the walls separating the tables area from the walkway. There is a relaxing area in the building with the Starbucks that has outlets. There are outlets in most of the guest relations locations. There are also outlets in the area around the Rapunzel bathrooms in the Magic Kingdom but there you will be competing with people trying to charge their phones.