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Using an Outdoor Handheld While Connected to External Power
Many of Garmin's outdoor handhelds can be powered externally while in use instead of using the batteries. Use of a 500mA standard USB output from a computer or vehicle USB port will not allow for powering the handheld all the way on in its default settings.1 Instead, the handheld will display a USB symbol against a blank background:
Connecting to a power source between 1000mA and 3000mA (twice to eight times the power of the computer USB ports) will allow you to operate the handheld from external power. Using an AC wall outlet or 12 volt Cigarette Lighter Adapter will provide enough power to turn the handheld on and use with external power.
Some vehicles have 12 volt ports that are only powered on when the vehicle’s ignition is on. This will cause the handheld to power on when you turn on the vehicle’s ignition and when the ignition is turned off, the handheld will begin a power off countdown (30 seconds). You will be given the options to continue on battery power, or turn off. If neither option is selected, the handheld will power off when the countdown expires.
1 If the handheld is in Spanner Mode, then it can be powered by a 500mA source. See your Owner's Manual to determine if your device has a Spanner mode. Some eTrex® and Rino® outdoor handheld models may call Spanner Mode "Garmin" in the interface.