Originally Posted by Sandroidfan
I don't know how your friend's GS3 are used but I never saw my friend's GS3 being always charged. All of them are saying it's easy to go over a full day and some more with GS3. Just because it has the same 2100mAh as Galaxy Nexus doesn't mean that battery life would be similar. The processor/radio chipset in GS3 is 28nm Qualcomm Krait, which is far more efficient than 45nm OMAP4, CMC221 LTE in Gnex. GS3 easily outlasts Gnex by long shot due to more efficient chipset.
Maxx HD has the same chipset as GS3 and almost identical HD SAMOLED screen. So between GS3 and Maxx HD, battery life difference will be simply matter of size difference. Also there are extended battery with capacity greater than 4000mAh for GS3.
The SGS3 has a bigger HD Super AMOLED screen and higher PPI than the Maxx HD.