The astronauts installed adapter plates and hooked up electrical connections for the final three of six new lithium-ion batteries .

Main objective was to prepare the PMA-3 for installation of the second IDA. They disconnected cables and electrical connections on PMA-3 to prepare for its robotic move.

They installed the first array on the far end of the left (port) side of the station's backbone truss structure (P6) to upgrade the 2B power channel.

The duo worked on the far end of the P6 to unroll the first of two iROSAs that will augment power capability for the port 6 truss' 2B power channel.

The spacewalkers installed the second solar array to upgrade the 4B power channel on the P6 truss.

They installed a support bracket on the inward port side of the station's backbone truss structure in a position known as P4. The crew also replaced a device that measures the electrical charging potential of the arrays.