I always enjoy reading Walt Mossberg’s articles for AllthingsD.com and I found this question and answer especially interesting and worth sharing. It really applies to all new digital devices with Lithium Ion batteries.
Q:
An Apple store employee told us that each Apple mobile device battery should be depleted to 0% once per month to keep its battery healthy. Is this necessary?
A:
That’s correct. Here’s part of the company’s advice on iPhone batteries: “For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Be sure to go through at least one charge cycle per month (charging the battery to 100% and then completely running it down).”
In its advice on laptop batteries, the company states, in part: “Apple does not recommend leaving your portable plugged in all the time.” It adds that, if you don’t drain and recharge your Mac laptop in the course of normal usage, “Apple recommends charging and discharging its battery at least once per month.”
Found Here.
I have a Garmin 1490T that I love and always use for navigation in the car. I found this information on all kinds of different information you can gain from your Garmin GPS. These should work with all Garmin branded devices and possibly some of their OEM installations.
Garmin Nuvi 1490T non-obvious screen access, hacks and undocumented features.
The list below was collected from a range of sources, including Garmin manuals, internet sites and my own experience.
Time
In main menu tap clock/time to access "Time” screen and one can change time format and the time
Return to main screen
From any screen hold finger on "Return" arrow where available and unit to will return to main screen
Lock unit, adjust screen brightness or turn off
Quickly pressing and releasing the power button from any screen to a new screen to Lock unit, adjust screen brightness or turn off. If left for 10 seconds the screen will disappear and unit revert to previous screen.
Customize the data field
On Map page, one can customise the data field on the lower left of the extended data display on the right, if enable. Tap the data field (Direction of travel, Elevation or Time of day) to select required field. There are additional items when navigating.
Save current location
From Map page, touch vehicle icon and touch "Save Location"
Satellite Display
On Main page, press and hold the upper left corner of the display (the GPS signal strength meter. It shows a sky map of the GPS satellites in view, as well as the current speed and latitude, longitude and elevation. It also shows the current estimated GPS accuracy.
SNR
In satellite display, press and hold finger on “Elevation" to display SNR Logging screen
System Configuration Displays
While running on batteries: press and hold the battery indicator at the top of the display. If on external power press just right of the time. Hold it until the display appears - this takes 5 seconds. This is the first of several pages that show all sorts of system configuration settings. While advancing through the screens (using the "next" button in the lower right corner), when the screen goes totally one color, continue to tap where the "next" button has been and it will continue to the next color. After "Exit" GPS restarts.
Track Log
Go to the "View Map" screen
Tap on the "Speed" indicator
Press and hold center of the speedometer until the “Diagnostics Page" appears (up to 10 seconds)
Select "Diagnostic Logging"
Select "Start Recording"
Check "GPX" then press "Start"
Log file is located in the "\.System\Logs\gpx"folder with the file name YYYYMMDD_XXXXXX.gpx (track log is already in GPX format).
Note: the "\.System folder is hidden (will not show upon the root dive in mass storage). You will have unhide hidden folders or type it in manually into the address bar (example "E:\.system\").
Usage Mode
Select "Usage Mode" by tapping on the vehicle symbol in Main page to select Automobile, Pedestrian of Bicycle.
How To Reset (Access Maintenance Mode)
Power off Garmin unit. Press continuously the bottom right corner of screen and then power on the unit by pressing once on the Power button. This can take up to 30 seconds. You should be prompted to clear all user data, or asked if do you really want to start up in maintenance mode. Press “Yes” to reset (warning: all data will be erased and lost, so backup before proceeding) or enter maintenance mode.
Screen Calibration (this is different from the help on the unit)
1. Turn device off
2. Put finger on upper left hand corner of screen & hold it
3. Power device on by a short press (may take up to 30 seconds)
4. You will get the calibration screen
5. Calibrate screen
6. Done
Info Found Here.
