It will conserve a lot of battery. Especially with the known signal problems of switching from 3g to 1x constantly.
Although, most people will make the argument that you shouldn't have to turn the mobile network off to get good battery life. That's the whole point of buying a smartphone. You shouldn't have to disable what it is meant to do.
Not so fast... It depends on whether or not you are in a strong signal area, whether you are roaming, et cetera.
Sort of analogous to the same way that a "dumb" cell phone will discharge itself extremely rapidly in rural areas with weak or non-existent service. Note that even for voice service, the tower and the handset frequently go through repeated "training" intervals where the handset power is adjusted. So, if you are in a weak signal area, or the tower can't "hear" your phone very well - your handset will dissipate a lot more power. There is no reason to believe that data services are any different - the network operator wants your phone to be able to stay in contact with the tower.
I ran two separate trials after the OTA update: in the first trial, I left mobile network on (and switched WiFi & GPS off), but avoided using the phone for anything but SMS, reading email, and a few voice calls. I put the phone back on the charger at 20% remaining after 37 hours.
In the second trial, I operated it in "dumb cellphone mode", turning off Mobile Network, Wifi, and GPS. After 14 hours, the phone was still at something like 95% charge, and I got fed up with the experiment... I didn't want to wait 5 or 10 days to run the battery down! So, I switched Mobile Network back on. Ended up putting the phone back on the charger at 62 hours. No, that's not a typo:
sixty-two hours.
In both of those cases, the phone was mostly used in a "3 or 4 bars" EVDO signal area (best signal -73 dBm); presumably staying in touch with the tower was not costing me much battery.
I guess the point is that in a weak signal area - where the phone is forced to boost its signal to maximum transmit power, or it is toggling back and forth between EVDO and RTT - it is easy to demonstrate that using the radio will cost you battery life. But that's nothing new - the same thing is true with voice service only.
It is overly simplistic to think that you can wander all over creation and always observe the same battery life with your cell phone; on the other hand, if you are aware of these kinds of behaviors, you can certainly adopt habits which will vastly improve time between charges - for instance putting the phone into Airplane mode when you know the phone will be unattended for long stretches of time, or toggling the WiFi on only when it's needed.
eu1
