According to Gizmodo:
Duracell, that company you used to buy batteries from, is sending out two giant charging trucks, allowing you to power up your mobile devices and use free computer terminals if you’re still out of Wi-Fi. The company sent us the details:
Tomorrow, Nov. 1, the Duracell Power Forward Community Center will be in Battery Park. Right now they are setting up at Battery Place and Little West St. (map). Open hours as of now are 9am-6pm.