For a while, I’ve been annoyed by the rather mediocre battery life of my Nokia N82. I do use it quite a lot – especially for Opera Mini, Gmail and music playback – and I have to recharge it every night. Some evenings the phone even runs out of battery before I go to bed.
What to do?
You can turn down the brightness of your display, but that makes for a poor user experience. And shutting down applications that are running in the background is also a good idea. However, none of these made all that much difference to the battery life of my N82.
Then I tried switching off 3G / HSDPA. It turns out that – in my highly unscientific measurements conducted with Nokia’s Energy Profiler utility – the N82 draws 0.4 watts when running with EDGE, about 0.7 with 3G and 1.3 watts (!!) when in HSDPA mode. This is with the phone idling and no transfers going on. I suspect that transferring data over 3G and HSDPA is relatively more costly compared to EDGE as well.
As said – these were highly unscientific measurements, so I may be wrong, but “field tests” (ie. me using the phone) have shown that while I normally charge it every night, I can now use it and charge every other night.
In other words – if you want to make the battery last longer – you should definitely try switching off 3G / UMTS / HSDPA and see if you get similar results.
What’s the downside?
Of course, you lose the 384 kbits to 3 mbits of bandwidth 3G and HSDPA provides (and the video telephony 3G enables), and have to live with the ~ 200 kbits EDGE can deliver. For me, this is no big issue, since the apps I use on the go are not bandwidth intensive (Opera Mini and Gmail both use very little bandwidth) and I don’t use video telephony. If I do need more juice, I am normally in a WiFi zone – or I can switch 3G/HSDPA on manually.
You can try turning off 3G/HSDPA by hitting the menu -> Tools -> Settings -> Phone -> Network -> Network mode -> GSM. This might look a bit different on your phone, as I have translated this directly from the Norwegian user interface. Wait a few seconds, and you should get EDGE coverage (if EDGE is provided by your local services provider).
You can see what kind of network you are currently on in the top left corner on the standby screen – E for EDGE, 3G for 3G, and 3.5G for HSDPA.
Good luck, and do let me know what kind of effects switching off 3G/HSDPA had for your battery life!
PS: I can only conclude that Steve Jobs was not lying when he claimed they dropped 3G from the iPhone due to battery life concerns. Seems that was at least partly true.