Get the
Gemini Firmware Updater and use it to do the software upgrade.
The recommended and maximum voltage for running a Gemini is 18v. You can get a 60W 12v to 18v DC-DC converter as a special order from
Snaptec. The part number is GB60-1218. Price around $AU200 with GST and postage. They also make a 12v to 15v that would work almost as well. Part number GB60-1215.