A:AnswerThe only thing you will need is the cables to connect to the devices you want to charge. Since the devices most likely came with those anyways, you should be good to go.
A:AnswerYes, I have a note 10 Plus and a Galaxy 10 Plus and plug both in at the same time. My wife has the 10 Plus and will work while I drive (she emails clients and calls) while I have Waze and Pandora running on my Note 10 Plus. Both plugged in at the same time and both charge while in use and plugged in to this car charger
A:AnswerIf the Magellan comes with a USB standard charging lead then yes sure you can plug the lead into this and it will charge and run your Magellan!
A:AnswerNo, you would get about 1.4 amps.
Wattage / Voltage = Current
17 Watts / 12 Volts (typical car voltage) = 1.4 Amps
Despite the amperage, this charger is faster than standard car chargers.