JBL EONONE-BATT - Spare Battery Module for EON ONE MK2This module acts as a spare or replacement battery for the EON ONE MK2 portable PA system. It mounts as the lowest part of the speaker column rather than inside of the subwoofer unit, reducing carrying weight when broken down. Up to two modules can be charged simultaneously in the dual charging unit (sold separately), and the rapid nature of system assembly means changing over to a fresh battery can happen with minimal disruption to the show.