Preparing the JEM ELM PS for its removal from the shuttle's payload bay.

Installing a spare space-to-ground Ku-band antenna on the station's truss. Then they installed a new tool platform on Dextre. The spacewalkers breaked the torque on bolts holding batteries in place on the truss.

Installing the final two new batteries on the truss and put the old batteries on the carrier. Next, they retrieved a grapple fixture from Atlantis' payload bay and brought it inside the station for use as a spare.