Segway Power Station Cube Install Extension Battery
This page details how to install an extension battery on a Segway Power Station Cube/Cube 1000/Cube 2000.
Process
Installation is relatively simple and all needed parts come with the extension battery.

Remove the parts and set them in a safe location, then remove the top cover.
Next, remove the antistatic bag and remove the extension battery.

Next, remove the two screws on the front using the included Allen/hex wrench from the main unit that you will be installing the extension battery onto.

Rotate the unit 180 degrees and remove the other two screws.

Next, place the extension battery on top of the base, taking care to align the connectors.

From here place the Control unit on the top, and install the original 4 screws and the new 4 screws from the parts bag into the unit.
The hardest part is making sure the holes are aligned as the screws may go in askew and strip if this is not done correctly.