The software for the D120 isn't done yet, so we can't have a manual quite yet. Anything the EMS-D10 can do, the EMS-120 can do. Thus metric units for fuel, temp, and pressure are all supported, just as they are in the EMS-D10.
Also, we do not support the battery backup in the EMS (10 or 120). If you really need a backed up engine monitor, you'll need a D180, or an external battery.