Consumer weblog "Which?" tested the most popular 7-inch and 10-inch tablets to compare battery life and found quite a bit of variation. If you're looking for a new tablet, here are some things to watch out for.
You can never really tell how an advertised battery life relates to real-world battery life, so "Which?" is here to help. Unsurprisingly, the iPad and the iPad Mini took first place in the 10-inch and 7-inch tests respectively. If you aren't an iPad fan, there's a lot to glean about Android and Microsoft too. For example, the 10-inch Samsung Galaxy Tab does a bit better than the Nexus 10, and a lot better than the Asus Transformer Prime (at least without they keyboard, since the keyboard contains an extra battery). At the same time, however, the Kindle Fire HD and Nexus 7 seem to do significantly better than the 7-inch Galaxy.
Obviously, battery life isn't everything, but it is something to keep in mind. Hit the link for more info on how the tests were run and for other details.