by cengel on May 23, 2011 at 5:18 pm
You all have probably seen the warning “continued use of GPS running in the background can dramatically decrease battery life” for mobile device apps. This is certainly true, but how much does it drain the battery and are there differences between different devices?
To get at least a sense, I took iPhone4, first generation iPad, and iPad2 on a test drive. The iPhone is about 10 months old. The iPad is 1 year old and iPad2 is 1 month old, both have with 3G. I fully charged each device. I used the GPS Kit application to track my position over a total time of about 8 hours. During that time I took a few intermittent data points. I closed any application except the GPS application and turned off WiFI. My results are graphed here:
During the first few hours, the first generation iPad drained even more than the iPhone, but then leveled off, while the iPhone battery continued to drain, down to less than 30%, after 8.5 hours. Not surprisingly, the winner is iPad2. However, I did not expect to see a battery level as high as it turned out to be. After over 8h of tracking iPad2 still maintains over 85% of its battery. This makes it — from the battery-perspective — possibly a contender in tracking devices.