Why Do I have Satnav Charger Problems?

Background
Users sometimes have problems charging their Satnav or other Garmin devices when not using the supplied Garmin charger / cable, the reason for this is that some Garmin units use special cables to set different 'Modes' on the unit.


FIG1

A normal USB Mini or Micro cable looks FIG 1, you will notice that the end that connects to Garmin has 5 pins not 4, this is standard to all USB mini and Micro connectors, it has always been there, but the 'ID' pin is not normally connected to anything, Garmin use the ID pin on some units to set the mode that the unit works in, NOTE other Garmin models do-not use the ID pin at all.

The units that use the ID pin have a cable that look like Fig 2 :-


Fig2

The ID pin is now connected via a Resistor to ground (GND) and the voltage on the ID pin is monitored by the unit to set the 'mode', It has been reported that an 18K Ohm resistor will place the unit in 1A charge mode and that zero Ohm will place the unit in 500mA charge mode


It is possible to check the charge mode (I Limit USB) on some units by holding the battery icon (top right) until a secret menu is displayed, the USB ID Volts is used to determin the cable type by monitoring the USB ID pin status



Here is a list of Nuvis that I suspect require a non standard USB cable (utilising the ID pin) :-
50lm 2595lmt 140 200 200w 205 205w 215t 250 250w 255 255w 260 260w 265t 265wt 270 275 275t 295w 300 310 350 360 370 40lm 465 465lmt 465t 500 510 550 650 660 670 680 750 755t 760 765t 770 775t 780 785t 805 850 855 880 885t 1100 1100lm 1200 1250 1260t 1300 1300lm 1300lmt 1350 1350lmt 1350t 1370 1370t 1390 1390lmt 1390t 1480t 1490 1490lmt 1490t 1690t 2250

Cable number :- 010-11478-03 and 010-10723-14

NOTE :- Genuine Garmin cables use 24 AWG power wires whereas cheaper USB cables use 28 AWG (or smaller), wires for all conductors, this thinner cable can cause problems when trying to charge / connect Garmin deivices