Archos V2 Jukebox Recorder input current measurement

I was just investigating the "external voltage" measurement on my Archos V2 Jukebox Recorder. I already knew it was actually current, and I was wondering if it is could be displayed at the charging screen. When charging via the charger input, it is an accurate measure of input current; just divide by 10 and you have the current in amps. When charging via USB, it still measures current, but the scale factor is different, with 7 V equalling 0.5 A.