The LCD (Liquid Crystal Display) uses approximately 33 percent of your overall power usage. The size of your screen can affect power consumption-a larger screen requires more power. However, the single greatest LCD culprit is your backlight-a small, fluorescent tube. The brighter the screen, the harder that tube has to work. You can dim the screen/LCD brightness and choose a working environment with adequate lighting-less bright means you'll drain less power from your battery.