Blackberry 8820 Current Draw

There are many articles which make vague mention of how to decrease power consumption and get longer battery life, but few are backed up by numbers. I hacked up a battery and put a Fluke 189 in the battery path in order to measure the draw for various cases. The results are below. Most measurements are a seven-minute average.

Idle States

Device Off1.01
GSM/EDGE802.11/UMABluetoothCurrent, mA

Calls and Additional Features

CaseCurrent, mA
UMA Call80
GSM Call110
GPS On, No Signal+ 37
GPS Tracking+ 42
Screen Backlight, 10%+ 12
Screen Backlight, 100%+ 120
Keyboard Backlight+ 23

How to Calculate Battery Life

To calculate the longevity of your battery, add up the current from the features you have active. Then take the capacity of the battery - nominally 1400 mAh - and divide by the current in mA. This gives you the runtime in hours. For example, if you were making a call on UMA at 80 mA, and also had full-brightness backlight on at 120 mA, for a total of 200 mA, you could expect 1400/200=7 hours of battery life.