While most of us have Smart Phones most of us also suffer from severe Battery drains on mid-range Phones. So what do you do when you are travelling, no charging point available and you need to give your Phone's Battery that extra Juice to last for some more time -
1. If you are travelling in a long distance train then it makes sense to put your phone in "Offline" mode when you train travels through remote places where you have less Network Towers. Your Phone spends the maximum Power searching for a Network rather than when you actually make a call.
2. While 3G has been rolled out in many countries including India few years back, the 3G coverage is not satisfactory according to my expectations and also the Voice / Data quality is poor. So if you are not using 3G for Data or connected to Wi-Fi it makes sense to put your Phone's Network Mode to "2G" which will save Power.
3. In many Android Phones I have found the following Network Modes available -
WCDMA preferred - Same as "GSM/WCDMA (auto connect)". Both 2G and 3G data capability, 3G favored more when signal strength is low
GSM auto (PRL) - 2G is favored more when signal strength is low. Both 2G and 3G data.
CDMA only - 2G data only, no data when 2G signal strenth is low.
EvDo only - 3G data only, no data when 3G signal strength is low.
GSM/CDMA auto (PRL) - auto-switching between GSM and CDMA capabilities.
Selecting GSM auto (PRL) will save some Power where 3G coverage is poor. (The information in Point 3 is courtesy: http://www.speedguide.net/faq/gsmwcdma-auto-or-gsm-only-setting-on-android-phone-408 )
With the information above I am pretty sure that when you land up in a Power-hungry situation you know what to do.
