The Galaxy Nexus sells with a 1850 mAh battery, but there is a OEM 2100 mAh available with a new back cover. The difference in thickness is minute, but it makes one wonder why they wouldn't have used the 2100 as the stock battery. Maybe it was to have the thinnest profile possible, or to make a quick buck off customers. The extended battery is only $25, but regular price is $50, and with the NFC chip embedded in the battery, it virtually eliminates any knock off manufacturers products from being very competitive. Let's hope the trend is more the way of the RAZR MAXX with a massive battery instead of the Nexus having a decent battery with a slight upgrade of an extended battery.