Originally Posted by geekmaster
The battery usage stats say that the display (backlight?) consumed 87% of the energy usage. It is on automatic brightness, used inside so it is not very bright. Wifi is on most of the time though. You cannot expect a light-emitting display to have a battery charge that lasts like on an eink device.
I've got an iPad, and I've used the Acer A100, Kobo Vox, and Samsung Galaxy Tab 7.0 Plus - I know what the battery lives tend to be like. The Acer A100 was one of the worst offenders, pre-ICS - then again, it's got a battery more suitable for a phone than a tablet. My main concern is background processes; on the Galaxy Nexus I have, for example, Maps has a Keep Awake time of 1-2 hours after 8 hours, with GPS being on for 40 minutes, and WiFi access for about as long as the Keep Awake.
I suspect that's Google Now's fault - and that may be why the XDA Nexus 7 forum has had quite a few threads about battery life. That, and the weird auto-brightness behavior; even at 10%, I find most of these screens adequate for inside use, as long as it's not TOO bright outside (think 500-1500 lux).