iPad mini Reviewby Anand Lal Shimpi & Vivek Gowri on November 20, 2012 6:10 PM EST
Battery Life and Charging
The iPad mini features an integrated 16.3Wh battery, easily smaller than the 43Wh unit in the iPad 3/4 but even smaller than the 25Wh used in the iPad 2. Given that the mini has roughly the same internals as the iPad 2,4, but with a substantially smaller battery, you can expect a corresponding decrease in battery life. The display is also smaller, which should reduce some of the power requirements a bit.
We've started running our new smartphone web browsing battery life test on tablets as well. If you missed its introduction in our iPhone 5 review, here's a bit about the new test:
We regularly load web pages at a fixed interval until the battery dies (all displays are calibrated to 200 nits as always). The differences between this test and our previous one boil down to the amount of network activity and CPU load.
On the network side, we've done a lot more to prevent aggressive browser caching of our web pages. Some caching is important otherwise you end up with a baseband/WiFi test, but it's clear what we had previously wasn't working. Brian made sure that despite the increased network load, the baseband/WiFi still have the opportunity to enter their idle states during the course of the benchmark.
We also increased CPU workload along two vectors: we decreased pause time between web page loads and we shifted to full desktop web pages, some of which are very js heavy. The end result is a CPU usage profile that mimics constant, heavy usage beyond just web browsing. Everything you do on your device ends up causing CPU usage peaks - opening applications, navigating around the OS and of course using apps themselves. Our 5th generation web browsing battery life test should map well to more types of mobile usage, not just idle content consumption of data from web pages.
The mini actually outlasts the 3rd gen iPad in our heaviest WiFi web browsing battery life test, but the 4th gen iPad's move to a 32nm SoC solves that problem. Under load however both the new iPad and the mini are fairly close in terms of battery life.
We haven't yet rerun our new test on all of the tablets, so we turn to our older 4th gen test to provide some additional reference points:
If we look back at our older test we get good perspective on everything. The iPad 2,4 still remains the king of single battery tablets, and the mini just barely makes it over 9 hours of use on a single charge. The mini still lasts long enough for it to be more of an all-day device than a notebook.
Our video playback test remains unchanged from previous tablet reviews. Here I'm playing a 4Mbps H.264 High Profile 720p rip I made of the Harry Potter 8 Blu-ray. The full movie plays through and is looped until the battery dies. Once again, the displays are calibrated to 200 nits:
Apple's video decode hardware implementation has always been stellar, as a result the mini manages to do very well here. At over 11 hours of video playback on a single charge, the mini is only bested by some of its larger iPad brethren. The iPad 2,4 remains insanely awesome here.
Our final cross-platform battery life test is the new GLBenchmark 2.5.1 Egypt HD test. Here we have a loop of the Egypt HD benchmark, capped to 30 fps, running on all of the devices with their screens calibrated to 200 nits.
I no longer have a 45nm iPad 2 so I don't have results for it here, but the combination of the small 1024 x 768 display and 32nm A5r2 silicon gives the mini better battery life than the iPads equipped with a Retina display. The iPad 2,4 continues to offer amazing battery life here.
The GLBench battery life test gives us a reasonable minimum for the iPad mini's battery life, with the video playback test giving us a good maximum. You can expect to see 6.4 - 11.2 hours out of a single charge from the mini.
The mini comes bundled with a 1A charger identical to what you get with an iPhone 5 or a 5th gen iPod Touch. Using the new Lightning connector it'll take about 4 hours to complete a charge on the iPad mini.