iPhone 3GS vs iPhone 3G real-world battery test: Over 45 per cent better

Let's compare these values with Apple's estimates for battery life, shown in a hand-knit table.

Apple says these are maximum values, and don't forget that we had screen brightness turned up to max and everything turned on that could be turned on -- and our iPhone 3G wasn't new out of the box.

So maybe it's no surprise that our findings of around 2.5 hours of talk-time on the iPhone 3G and 3.75 hours on the iPhone 3GS are way below the max value of 5 hours that Apple claims.

And our test over Wi-Fi got us 5 hours on the 3GS, not 9 hours, and 3 hours on the 3G rather than the 6 hours advertised.

With over 45 per cent improvement over the iPhone 3G in both our tests, the iPhone 3GS lives up to its claims of battery superiority. And it's interesting to note that the 3GS out-performs its older cousin even when Apple says that the talk-time over the 3G network is the same.

Our American cousins over at CNET.com did a straight talktime test on EDGE, and managed almost 11.5 hours of battery life, compared to the iPhone 3G's results of 8.75 hours.

The upshot is that yes, battery life on the iPhone is diabolical... but it's significantly better on the iPhone 3GS. So if you're pondering whether it's worth the investment in the £100-more-expensive 3GS, consider how long you're likely to spend away from the plug.

You should also check out our comparison of the twin iPhones' other features to help you choose.

And whether you decide the future is now with the iPhone 3GS, or kick it old-school with the iPhone 3G, you'll need Apple's tips on how to conserve battery life. Who knew? All you have to do is turn all the good stuff off.