Power modes

Power Modes

Without switching the device entirely off, it may be placed into low power mode or regular power mode; simply pressing the power button will toggle modes. Note that as of hotfix3, opening the lid will always enable the backlight. The cpu speed will not change, you need to use the power switch again (and wait for the scripts to run)

Normal Mode

This is the normal operating mode, screen on, WiFi and Bluetooth on if requested. CPU speed can be selected by the user, and has a small impact on battery life. Screen brightness will also have an effect. The CPU should automatically self-regulate to the current task, and 10-14 hours battery life is possible depending on usage. At any time, the battery gague will show the remaining battery life if the usage remains the same as over the past some seconds.

Lid Closed

The only change with the lid closed is to turn off the LCD backlight. This improves battery life, allowing music playback and streaming to continue. As of Hotfix2, the screen remains on if the device is powered up with the screen closed.

Low Power

Low power mode is toggled by a short press of the power switch to the right. The screen is off, the radios are disabled, the CPU max speed is set to 14 MHz. The device is still silently on, allowing for alarms to go off or it to be turned on again instantly.

Low power mode is probably going to be used as the normal "off" for most people, with true off (device powered down entirely, unable to respond to alarms or wake up quickly) available to conserve battery power. Turning the Pandora off completely is the best option if you don't plan on using it for few days or longer.

Since the Pandora has to be powered whilst it is charging, low power mode is best for fastest charging, and will even allow a full charge to be achieved from USB.

Opening the screen whilst in low power mode currently enables the screen, but leaves the clock at 14 MHz. You can use the power switch to return to the previously selected clock speed (this behaviour is under discussion [as of hotfix3], some find it confusing since it is not symmetrical, and the power switch has a different function depending on the state)

At the moment, there is no clear advantage in slowing the clocks (other than being an effective pause button when playing MP3). The only saving is through disabling the radios. This is likely to be improved in due course since there are features in the omap processor for power saving which are being added to the linux kernel.

Power Off

Select Logout then Shutdown from the window manager to power off. If a charger is connected, the device will re-boot immediately. It is possible to get into a state where you believe it is powered off, but in fact it is using power at the normal screen off rate - so after 12 hours, 50% of your battery is gone. The Power green LED ought to be a tell-tail. It is possible that some bugs exist in this area, but nothing has been clearly identified[1]

A common problem seems to be that if you switch off before unplugging, your Pandora will re-boot even though it is now left unplugged. This problem is compounded by the low battery shutdown script being called repeatedly (and actually preventing shutdown).

Events

The events which control power can be customised [2]. Lid switch, Power Switch, battery threshold and Window Manager shutdown commands. Note that the battery manager in xfce will also take action when the battery is low, by default forcing a shutdown at 5% (so you may observe a full boot process, the window manager appears, then immediately shuts down)

Charging

It is possible to charge from the mains charger (use the supplied one or a GENUINE PSP adaptor only) or USB cable. While a charger is connected, remaining battery level is displayed, but the time displays 00:00. If charging from USB, it is possible that the battery will still discharge slowly, since the Pandora takes more current (in normal mode) than the USB can supply.

Times

(These are my estimates, should be clarified once more user data exists)

Charge/Discharge times

Mode	Time
Normal Operating	10-14 hours
MP3 play, screen off	17 hours (May improve)
Lid Closed	16-23 hours (est, depends on wifi)
Low Power	23 hours (est, should improve)
Power off	less than 5% per day charge loss (est)
Mains charge, operating	20 hours (est)
Mains charge (low power)	8 hours (est)
USB Charge, operating	20 hours (inactive, screen+wifi on), may charge or discharge depending on load
USB Charge, low power	20 hours (est)