It is a bit like a double edged sword... Many older 3G devices eat power like hell just being on 3G without any active data connection etc. Just the normal being able to receive calls.

However, there is a very significant power saving in N900 there than on my old Nokia E70 for example. Not sure how well other modern 3G phones do than N900 though. N900 can handle 9.1 days of idle on 3G and 3.1 days of idle with 3G data connection on but idle.

It is true that data transfer on 3G eats power like there is no tomorrow. I suppose the worst efficiency on 3G is when there is some data going constantly but the amount of data is very small.

On other hand, while browsing for example, the time it takes to load a page on 3G is so much faster than on 2G that you might actually save power. Eg. 2 Mbps 3G and 0.2 Mbps 2G gives you 10 times the download time for a given page (assuming the server you download from is fast enough) on 2G. So, 10 times longer of moderate battery usage compares to short heavy battery usage. It would take more experimenting to know how it goes. And signal quality etc will matter of course.


Good old memories with E70 and 3G... When I had some problems with my normal connection, I used E70 as internet connection for my main comp and played Spring (open Total Annihilation remake sort of).. The transfer speed was low, but it was constantly transferring data on both directions, so I once even noticed the the charger was too slow to charge the phone so the battery died while being charged!