The iPad has a 10 hour battery.
Apple used to be liberal with it’s battery claims. My old rule of thumb for looking at Apple laptops was to halve the time estimates. My 2008 Macbook Pro gets 2-3 hours instead of the quoted 5.
With the advent of non-removable batteries, the numbers are getting much better, with the latest Macbook Pros getting 7 hours of battery life.
But there’s a major difference with the iPad: it’s standby mode lasts a month. And it comes in and out of standby instantly. So unlike a laptop, which stays on for as long as I keep the lid open, there isn’t any downside to letting the iPad fall asleep and waking it back up. So even if the iPad only gets 7 hours of battery, that’s 14 thirty minute sessions with the device. If it sits in my living room and gets picked up by anyone needing the internet, it’s battery will likely last a week. If I toss it in my bag and use it whenever I need to surf the web, it will at least last a couple of days of fairly regular use.