What 'Nuvi' is best Value for Money' to use on a Motorcycle?

[legtu]

I think I have found a nice' high tech solution, for providing a 'Visor' to keep the strong sunshine off the screen, whilst keeping the Garmin Nuvi powered up all the time and does so for more than double the length of time, than running on 'Nuvi Battery'.

This being the use of a SBC-10 '2000mA Solar battery Charger' from CDR King (Php580), containing a 3.8V Lithium Cell.
It can be charging the Lithium Cell, whilst connected to the Garmin Nuvi, so the drain on the internal Nuvi Cell is minimized so it lasts longer. If you disconnect (or bump/vibration causes such) from a USB 5V Power Adapter, the Internal Lithium Battery and/or the Solar Cells keep the Garmin Nuvi from shutting sown and rebooting.

The SBC-10 from CDR King, has a length, that is the same Width as a Garmin Nuvi 255, so (suitably mounted) it can act as a 'Sun VIsor' that generates Power and has a reserve 2000mA of Lithium Battery Power, giving extended UPS capability, and off-bike Power.

a couple of things to consider with regards to using the portable solar batt pack...
- max output current of the solar panel is 100ma, and that's with a good amount of sunlight shining on the panel. that's barely enough to charge the internal battery of the power pack itself
- afaik, the solar panel works as a charger for the internal batt only
- there's converter loss that you have to factor in when using the usb output of the power pack. best case would be around 90% efficiency or more, realistically, it might be around 80% or less.

[Borgie]

Borgie,

I am a bit confused about your Garmin Nuvi 255, that you also bought from Amazon, not being shipped with a 'cradle' that 'fits'?

The 'standard' Nuvi 'cradle' is a plastic clip that fits over the back of the Nuvi, and engages in a slot in the bottom, then 'snaps' into place at the top (that is narrower!).



Since I also bought a Nuvi 265W at the same time, which is same height, but 'wider' (hence the 'W'), I can confirm that the same 'cradle' snap clip, is used.

So Borgie, this is why I am confused as to your saying "the cradle is about 3/8" bigger and just wouldn't fit duh:"
Unless, you were trying to fit the cradle clip on upside down - duh!,
i.e. you had the wider bit at the top instead of the bottom?

Sorry Borgie, but that is too obvious - right? If you were supplied with that same standard 'clip', it should fit any Garmin Nuvi - even the 'W' versions? (provided it is the correct way up with the wider bit at the bottom)

Sorry Britster, came across your reply just now. Anyways, yes the cradle is indeed 3/8" bigger/longer and methinks it's made for another Nuvi model whose width is wider than the 255. Please see attached pic, notice that the upper lip that will engage the slot in the Nuvi is located lower and is angled 45 degrees. Since this is a refurbished unit, can't really complain much as it would be too much hassle to return. I have plans of cutting it down then gluing the cut parts... but haven't found the time just yet

[Britster]

Sorry Britster, came across your reply just now. Anyways, yes the cradle is indeed 3/8" bigger/longer and methinks it's made for another Nuvi model whose width is wider than the 255. Please see attached pic, notice that the upper lip that will engage the slot in the Nuvi is located lower and is angled 45 degrees. Since this is a refurbished unit, can't really complain much as it would be too much hassle to return. I have plans of cutting it down then gluing the cut parts... but haven't found the time just yet

Strange that Amazon.com shipped with the wrong Nuvi 'Clip' mount?

Apart from any physical size difference, the upper retention 'lip' on the Clip Mount you have, seems to protrude from the 45 Degree angle section inside of sticking out from the underneath of that Top section.



If that retention lip being in the wrong place was all that was wrong (ie filed off, the Clip would physically fit the Nuvi255), I would create a new retention lip in the correct place. I would add some mechanical stength by drilling two small holes so they align with the ends of the 'groove' in the top of the Nuvi 255, ad fit tiny self-tapping screws that protrude, from the 'Clip' Mount, into the notch on the Nuvi 255.

I would then use steel filled epoxy resin (as it stronger, and black) poured into a 'mold' (thin strip of masking tape wrapped around the screws). When that hardened, remove the masking tape, and add another thin layer of epoxy, to cover the screws and over the in filled epoxy. File to correct height, width, and length, with rounded corners and edges.

If that too much bother, you could try to get the correct one off Amazon.com If they insist of sending back the incorrect one, probably just as cheap to buy a new one?

Navitech clip bracket back plate mount for Garmin Nuvi 200, Nuvi 200w, Nuvi 205, Nuvi 205w, Nuvi 250, Nuvi 250w, Nuvi 255, Nuvi 255w, Nuvi 260, Nuvi 260w, Nuvi 265t, Nuvi 265w, Nuvi 265wt, Nuvi 270, Nuvi 270w, Nuvi 275t
by Navitech

Price: £1.99



Price: US $3.99

FOR Garmin Nuvi 200w 205w 250w 265wt GPS Suction Mount

[Borgie]

Strange that Amazon.com shipped with the wrong Nuvi 'Clip' mount?

Apart from any physical size difference, the upper retention 'lip' on the Clip Mount you have, seems to protrude from the 45 Degree angle section inside of sticking out from the underneath of that Top section.



If that retention lip being in the wrong place was all that was wrong (ie filed off, the Clip would physically fit the Nuvi255), I would create a new retention lip in the correct place. I would add some mechanical stength by drilling two small holes so they align with the ends of the 'groove' in the top of the Nuvi 255, ad fit tiny self-tapping screws that protrude, from the 'Clip' Mount, into the notch on the Nuvi 255.

I would then use steel filled epoxy resin (as it stronger, and black) poured into a 'mold' (thin strip of masking tape wrapped around the screws). When that hardened, remove the masking tape, and add another thin layer of epoxy, to cover the screws and over the in filled epoxy. File to correct height, width, and length, with rounded corners and edges.

If that too much bother, you could try to get the correct one off Amazon.com If they insist of sending back the incorrect one, probably just as cheap to buy a new one?

As i mentioned in my previous post, not only is the lip angled the wrong way, but the cradle is also longer so there's a 3/8" gap between the top of the nuvi and the lip. That's why i mentioned that i planned to cut it down (maybe nearer the centerline of the cradle) slide it lower, then glue, so that the top lip can connect with the top of the nuvi. Thanks for the tips and the links...

[Britster]

a couple of things to consider with regards to using the portable solar batt pack...
- max output current of the solar panel is 100ma, and that's with a good amount of sunlight shining on the panel. that's barely enough to charge the internal battery of the power pack itself
- afaik, the solar panel works as a charger for the internal batt only
- there's converter loss that you have to factor in when using the usb output of the power pack. best case would be around 90% efficiency or more, realistically, it might be around 80% or less.

Hi 'Legtu',

I am not expecting the Solar Cell to Power the Garmin Nuvi

I bought it because of its Size and Price (Php580), and its 2000mAh Lithium Cell Battery, together with the supplied connector leads.

The standard Garmin Nuvi Battery is 1250mAh



So if 1250mAh gives about 3 hours battery life to a Garmin Nuvi 255, having another battery of 2000mAh connected to the USB on the Nuvi, will more than double the usability time of the Nuvi. This is without it getting charged from the sun at all, or connected to my motorcycle 12V power outlet socket with a Dual USB adaptor.

With the leads supplied I can also charge my Nokia N95 8GB from the other USB Socket.

If that USB Power Adaptor vibrates loose whilst riding off road on some rough sections, that internal battery and the Solar panel will maintain the voltage at the mini 'B' USB connector into my Garmin Nuvi 255, so it does not go into PC connect mode then 20 seconds later reboot.

Well worth Ph580 even if all that Solar Cell does is stop the battery from going flat completely.

'Legtu'

Have you ever tried pressing the Battery Icon on your Nuvi for 5 seconds, and it should go into DIAGNOSTICS Mode with information on the Battery Current (70ma), Battery Voltage (4062v) and show the I Limit is 150mA, VMAX (4.70v)

The above was when connected to my PC via USB, unplugging so it running off the Garmin Nuvi 255 internal 1250mAh battery these are currently:-

Battery Current (21-40ma), Battery Voltage (3860v) and show the I Limit is Unknown, VMAX (3.86v), Batt Capacity (81%)

Plugging back in to the PC some 10 minutes after running off battery, via USB, saw Battery Current (110)

So getting 100ma from the Solar Panel, will certainly help extend the battery life, as and when it disconnected from my Motorcycle with the 1250mAh internal Nuvi Battery and the 2000mAh of that SBC-10 Solar Powered Battery Pack (costing Php580) and providing shade for the Screen of my Garmin Nuvi 255 at the same time.

[legtu]

I am not expecting the Solar Cell to Power the Garmin Nuvi

and you shouldn't.

If that USB Power Adaptor vibrates loose whilst riding off road on some rough sections, that internal battery and the Solar panel will maintain the voltage at the mini 'B' USB connector into my Garmin Nuvi 255, so it does not go into PC connect mode then 20 seconds later reboot.

Well worth Ph580 even if all that Solar Cell does is stop the battery from going flat completely.

just like i said in my previous post, afaik the solar cell only works as a charger for the internal battery for the power pack itself. it doesn't provide any power to the usb output.

So if 1250mAh gives about 3 hours battery life to a Garmin Nuvi 255, having another battery of 2000mAh connected to the USB on the Nuvi, will more than double the usability time of the Nuvi. This is without it getting charged from the sun at all, or connected to my motorcycle 12V power outlet socket with a Dual USB adaptor.

imo, with a best case scenario, the solar pack *could* double the runtime of the nuvi. in reality, there are losses in between the 2000mah batt and the converter (which provides the 5v output), the charging/power circuitry of the gps device and the actual charging process itself.

[arvin555]

I am not sure if this was addressed already or not. I like the idea of having a separate battery pack, specially for bikers and cyclists.

However.

1. CDRking device you mentioned only outputs at 3.7V or 3.8V?
2. Garmin Nuvi needs 5V for charging.

I imagine that the 3.8V battery will not be enough to give the Nuvi Juice, unless of course you already know for a fact that Garmin only really needs 3.8V to work?

My two cents.

TTFN
Arvin

[Britster]

I am not sure if this was addressed already or not. I like the idea of having a separate battery pack, specially for bikers and cyclists.

However.

1. CDRking device you mentioned only outputs at 3.7V or 3.8V?
2. Garmin Nuvi needs 5V for charging.

I imagine that the 3.8V battery will not be enough to give the Nuvi Juice, unless of course you already know for a fact that Garmin only really needs 3.8V to work?

My two cents.

TTFN
Arvin

Arvin,

As Legtu mentioned, many Battery Packs that offer USB output (so it can power many small devices like cell phones, GPS Navigators etc) have a DC-DC inverter chip. The output is 5V DC


I was considering a 4 x AA Cell Battery Pack, and using rechargeable Sanyo 'eneloop' batteries. This would give 4.8V output so no regulation or DC-DC inverter would be required.

But a 4 x AA 'eneloop' Batteries cost Php580 from CDR King.

So I think that the SBC-10 for same Price is better, for following reasons:-

1. No need for a 'Battery Holder'
2. Small compact size - same width as Nuvi 255
3. Can use Solar Cell as 'shade' for the screen of my Nuvi
   (and generate power to keep battery topped up)
4. Cables for charging from USB supplied
5. Adapters provided for Mini B USB and Cell Phones
6. Built in Torch
7. Solar Panel for keeping Nuvi internal 1250mAh Battery topped up

A Garmin Nuvi is only consuming 50mA or so when not searching for satellites (from the Diagnostic Screen info).

The Solar Power can generate up to 100mA, so even allowing for energy losses of electronic circuitry, the solar panel will reduce the losses, from the internal Garmin Nuvi Battery, with the SP-10 connected.

I do have a 12V DC Power outlet on my motorcycle, but off-road use can sometimes disconnect the Garmin adapter with bumps and vibrations.

When using the USB adaptor in that 12V socket, and such disconnection is disastrous! It stops the Garmin from Displaying and Logging! Even reconnection means USB Mode, followed 30 seconds later by loading Maps.
Having this SBC-10 connected in between maintains voltage to the Garmin so no re-boot and no loss of Display, and no loss of logging (which for me, is not a problem for RoadGuide contributions, since I usually using my WBT-201 no logging at 250ms on bends).

[arvin555]

Thanks for the clarification. Please double check though if this solar system does have a DC to DC converter for 5V, I agree it probably does, but please just confirm. If it does, then go for it.

What is the difference again between the connection of your 12V charger and the Solar? Or is it the 12V connection between Bike and Charger and not the Charger to the Nuvi?

Also please double check the charger you use, I am using the original Garmin Cigarette lighter charger, and even if I plug and unplug several times, it will never go into USB mode, because there should never be a signal to tell the Nuvi that it is connected to a computer. That is my experience at least.

TTFN
Arvin

[Britster]

Thanks for the clarification. Please double check though if this solar system does have a DC to DC converter for 5V, I agree it probably does, but please just confirm. If it does, then go for it.

What is the difference again between the connection of your 12V charger and the Solar? Or is it the 12V connection between Bike and Charger and not the Charger to the Nuvi?

Also please double check the charger you use, I am using the original Garmin Cigarette lighter charger, and even if I plug and unplug several times, it will never go into USB mode, because there should never be a signal to tell the Nuvi that it is connected to a computer. That is my experience at least.

TTFN
Arvin

Arvin,

SBC-10
2000mAh Solar Charger
Php 580.00







As you can see, kn this there is a USB 'A' socket (like on your PC), and a USB Mini 'B' socket (like on the back of a Garmin Nuvi).

Because I mount my Garmin Nuvi 255 in a Water-resistantHandleabar Mount Case, the standard cable supplied, having Mini 'B' USB or via Multi Adaptor connector, protrudes too far to fit the depth of the case. I have a short USB 'A' (Right angled), to Mini 'B USB (Right angled) cable.

I do have the standard Garmin 12V DC (cigar lighter plug) Adaptor with the Mini 'B' USB, but this sometimes disconnects, on off-road sections, due bump shocks and/or vibrations.

I can't then also be charging my WBT-201 or Nokia Phone, if using that 12V DC Power outlet for the Garmin Power Adapter!



Powering the Garmin Nuvi from this USB 5V DC Power Adapter, also allows the other USB Socket to connect to my WBT-201 at the same time, so it can stay charged longer, or I can be charging my Nokia N95 if that complaining its battery is going flat!

The USB adaptor, is much smaller and lighter, than the Garmin Cigar Lighter Power Adaptor.

So there are a number of advantages to powering from a USB Power outlet, that plugs into the Waterproof Cigar Lighter Socket I mounted and wired to my XT225 12V Battery (via a Fuse), rather than from the 12V to 5V Adapter from Garmin.

The advantage of the Garmin Cigar Lighter Plug Power Adapter, being that if it gets disconnected at all, a warning "External Power Lost. Tuning off in 29..28..27.. Continue on Battery Power?
You can select <Turn Off> or <Stay On>

When Powering a Garmin Nuvi' from a USB power source, it boots up and says "Loading Maps..." but these don't Load, as it then switches into PC Connect Mode the Green 'Loading bar' display starts, but then stops. However after 20 seconds, it seems to realise there is no PC connected, and boots normally and loads the Maps this time.

With that USB Power Adapter, removing the USB from the 12V DC Socket (as opposed to removing the USB Cable from the USB Power Adapter), it repeats the initial power up. On my Motorcycle, when that happened due to bump or vibration, I lost the Navigation Screen, and the tracking. I missed a WayPoint marking a turn for a new Track, not on RoadGuide.ph.

So if I did not want that happening, yet still preferred the Dual USB Adapter over just the Garmin Power Adapter in my 12V Socket on my XT225, I needed a solution to prevent the 'Reboot, should that USB Adaptor come loose and lose electrical connection.

Wrapping PTFE Tape areond the top of the USB Power Adaptor has made it a tighter fit, and perhaps less chance of coming loose and loosing power input, but I wanted some 'insurance' in case it still happened.

That SBC-10 for Php580 is that 'Insurance', and can charge mu Nokia phone, and be a torch in the dark, and top its internal battery up when the sun is shining.

For the same price as 4 x AA Sanyo 'eneloop' batteries, I am well pleased with it.

The only negative thing I have noticed, when plugging and unplugging and leaving on charge via the SBC-10, whilst the SBC-10 also plugged into a USB Socket (as I will be using on my XT225), and going to the Diagnostic Screen to get information that it is Charging and what current and Voltages are showing, it did show against 'Battery:' "NTC Fault" and was no longer Charging.



Garmin nüvi forums
Tip - Using your Nuvi while it is plugged into PC

Originally posted by HRS - 26 May 2008

For what it's worth, I tried method #2 on my Nuvi 260. It does work, but immediately afterwards the battery would not charge even when connected to the Garmin car charger. (Until then, I'd *never* had any problem with the unit.)

I went into the diagnostic menu (hold down the area where the battery icon is located) and it showed an NTC battery fault, whatever that is. The only way I could restore normal charging was to CLR Checksums and run the full diagnostic routine. Then, the battery status was reset to normal and the unit did resume charging normally using the Garmin charger.

So, I'd advise some caution trying to "fool" the Nuvi 2xx series into working as a GPS when connected via a USB cable to a computer.

I discovered from a Google Search 'NTC' (Negative Temperature Coeffi cient) as well as this Thread!

Seems the Garmin Nuvi may have a 'thermistor temperature monitoring circuit, to make sure the battery does not overheat. If the voltage at that NTC input is above a given threshold, the NTC Fault is activated which kills the charging until if the Thermistor signals to the NTC input, the battery has cooled, ie voltage back down below the NTC Signal Threshold.

So I am wondering if your restore normal charging by "CLR Checksums and run the full diagnostic routine" did fix the problem or just take time, with no charging gong on, and the battery cooled down, and lowered the voltage to that NTC pin input, so the NTC Fault was removed and charging able to commence again?

Just leave it for 30 mins (or as long as the Full Diagnostic Routine takes to complete) and see if that NTC Fault clears on its own (as the battery cools down)?

Not saying this is the case but sound logical from a Datasheet on a Battery Charger Control Chip. This has an 'NTC' Negative Temperature Coefficient) Monitor pin that a Thermistor connects to.

....

Whilst Testing with the Diagnostic Screen, to see if it was charging and what the voltages and charging current were, I got this

NTC battery fault

The Google Search also brought up this Thread!

I thought I would add what I found out about NTC, and why I was searching for what 'Battery NTC Fault',meant.

David

[arvin555]

With that USB Power Adapter, removing the USB from the 12V DC Socket (as opposed to removing the USB Cable from the USB Power Adapter), it repeats the initial power up. On my Motorcycle, when that happened due to bump or vibration, I lost the Navigation Screen, and the tracking. I missed a WayPoint marking a turn for a new Track, not on RoadGuide.ph.

This is what mean. You probably need to check how Garmin charger is wired, because with the Garmin Charger, it will never go into "PC mode" at all. This is what you want to copy for your Non Garmin USB to Mini USB cable that you use.

http://pinouts.ru/Slots/USB_pinout.shtml

Above shows the pinouts, I suspect that maybe for some reason there is some kind of signal going to pin no. 2 and 3 in your USB cable, you could try to scrape off the connection from the USB side to prevent the Garmin device from thinking it is being plugged in a PC, which might be causing that sudden reboot thing that you get.

As for the device, from CDRking, I think it is interesting, specially as an emergency backup for charging GPS or Cellphones.

TTFN
Arvin

[Britster]

This is what mean. You probably need to check how Garmin charger is wired, because with the Garmin Charger, it will never go into "PC mode" at all. This is what you want to copy for your Non Garmin USB to Mini USB cable that you use.

http://pinouts.ru/Slots/USB_pinout.shtml

Above shows the pinouts, I suspect that maybe for some reason there is some kind of signal going to pin no. 2 and 3 in your USB cable, you could try to scrape off the connection from the USB side to prevent the Garmin device from thinking it is being plugged in a PC, which might be causing that sudden reboot thing that you get.

As for the device, from CDRking, I think it is interesting, specially as an emergency backup for charging GPS or Cellphones.

TTFN
Arvin

Arvin,

Thanks for that website http://pinouts.ru/Slots/USB_pinout.shtml
Really good and comprehensive information on USB connectors, Specifications, Pin Outs, and even what gauge wires should be used.

Dedicated charger mode:

A simple USB charger should short the 2 data lines together. The device will then not attempt to transmit or receive data, but can draw up to 1.8A, if the supply can provide it.

Perhaps I need to buy new Cables but research the Pin outs so it is a Power Cable as opposed to Power + Data.

I guess I could cut the cable open, and short the 2 x Data leads (white to Green)?

I think I will also contact GriffinTechnology.com to ask about their 'Powerjolt Dual Universal USB Micro' to discover if they short pins 2 & 3 and if not, ask why not?



http://www.griffintechnology.com/sup...niversal-micro

[Britster]

Here are some photos of that SBC-10 Solar Charger /20000mAh Battery pack mounted on the top of a clip on prototype 'Visor' I made to shade the Nuvi 255 Screen:-







If I purchase a RAM Mount, I may design a better Visor solution that dos not need that Akron GPS032 Case, as I will fit the Garmin Nuvi in a Water resistant plastic sleeve, custom made for the Garmin Nuvi.

I did produce such a plastic sleeve for the SBC-10 to protect it from rain, as you can see in those photos.

[Britster]

SBC-10

Specifications:

Solar panel (poly-crystalline): 5.5V 100mA
USB charging cable: 5V 500mA (current limited)
Constant Voltage: 4.2V (to save internal battery power)
Internal Li-ion battery: 3.7V, 2000mAh
Output: 5.5V/500mAh
Super long standby time: more than 3 months
Charging by USB cable: The indication bar will turn blue incrementally until fully charged
Charging in sunlight: One LED will turn red during charging
Protection: Charging current limited, discharging current limited, protection from overcharging, discharging, over current short circuit



Scanned image from back of CDR King Box of SBC-10attached.

I am not sure if this was addressed already or not. I like the idea of having a separate battery pack, specially for bikers and cyclists.

However.

1. CDRking device you mentioned only outputs at 3.7V or 3.8V?
2. Garmin Nuvi needs 5V for charging.

I imagine that the 3.8V battery will not be enough to give the Nuvi Juice, unless of course you already know for a fact that Garmin only really needs 3.8V to work?

My two cents.

TTFN
Arvin

[Britster]

This is what mean. You probably need to check how Garmin charger is wired, because with the Garmin Charger, it will never go into "PC mode" at all. This is what you want to copy for your Non Garmin USB to Mini USB cable that you use.

http://pinouts.ru/Slots/USB_pinout.shtml

Above shows the pinouts, I suspect that maybe for some reason there is some kind of signal going to pin no. 2 and 3 in your USB cable, you could try to scrape off the connection from the USB side to prevent the Garmin device from thinking it is being plugged in a PC, which might be causing that sudden reboot thing that you get.

...

TTFN
Arvin

Arvin,

From that same website that you found USB info and gave the URL:-



Garmin Nuvi GPS Power Connector connector pinout

GPS connector or cable wiring scheme


5 pin mini-USB plug connector


Wiring diagram pinout to place Garmin Nuvi, Oregon and GPSMAP 62 GPS in recharge mode.

Pin........Pin
..........Name.......Description
1 ........+5V.........5 volts DC
2 .......data ........not connected / float
3 .......data ........not connected / float
X .......GND ........connected to pin 4 (GND) with 17.3K ohm resistor
4 .......GND ........ground

Standard 5 pin mini-USB connector has pin X connect to ground (pin 4) through a 200K ohm resistor (Note: The normal USB connector has only 4 pins, the mini-USB has 5 pins).

To place Nuvi into charging mode, the 200K ohm resistor must be changed to 17.3K ohm. (also successful with 22K ohm resistor from Radio Shack, also a cheap 1/8W, 5%, 15k ohm resistor will work just fine!)

Nuvi behavior depends on mini-USB plug connection.

(IMHO) it is like this:
pin X not connected - data cable, nuvi connects to PC as removable drive, navigation NOT possible.
pin X & 4 short-circuited - USB supply 500mA, possible navigation,
pin X & 4 connected through 18kOhm resistor - Garmin supply 1A, possible navigation.
pin X & 4 connected through 22kOhm resistor - Garmin supply 500mA, possible navigation.

I personally modified a cable that connected pin X to pin 4 (shorted), and verified the 500 mA charge behavior as noted above.

Nuvi requires 1000mA for simultaneous charging + GPS operation [many 'generic' 12VDC-to-USB adapters output a maximum 500mA]

Garmin Oregon requires a resistor of at least 47K ohm for running in external power supply mode (100K ohm also works). Smaller values are working, too, but Oregon then first shows a message that an unsupported accessory was found.

GPSMAP 62:
pin X not connected - data cable, GPSMAP 62 connects to PC as removable drive.
If it fails because it is connected to your car battery, it switches to external power supply mode after several secondes.

pin X & 4 connected through 47 k Ohm resistor - GPSMAP 62 switches to external power supply mode immediately without waiting.

USB (Universal Serial Bus) designed to connect peripherals and exist in a wide variety of digital devices.

Pin .....Name.....Cable color ......Description
1 .......VCC .......Red ................. +5 VDC
2 .......D- .........White .............. Data -
3 .......D+ .........Green .............. Data +
X .......ID ................................ May be N/C, GND or used as an attached device presence indicator (shorted to GND via resistor)
4 .......GND........Black................ Ground

USB pinout signals

USB is a serial bus. It uses 4 shielded wires: two for power (+5v & GND) and two for differential data signals (labelled as D+ and D- in pinout). NRZI (Non Return to Zero Invert) encoding scheme used to send data with a sync field to synchronise the host and receiver clocks. In USB data cable Data+ and Data- signals are transmitted on a twisted pair. No termination needed. Half-duplex differential signaling helps to combat the effects of electromagnetic noise on longer lines. Contrary to popular belief, D+ and D- operate together; they are not separate simplex connections.

So it is a Resistor Value between the 5th Pin 'X' and GND, that needs to be changed to allow the Garmin to Charge and Navigate correctly!

If this is internal to the 'moulded' Mini 'B' USB Plug, it can't easily be changed. So the answer, if there is a Wire for Pin 5 is to add 20kOhm resister between Pin 'X' and Gnd.

If Pin 5 of a molded Mini 'B' USB Plug, has no wire attached to it, then one can't easily alter the value of any resistor connected to that and 'GND'.

If Pin2 (White), is shorted to Pin 3 (Green), then the Garmin should hopefully then see this as a 'Power Cable', and not attempt 'PC Connect' mode. This did not work, so Garmin does not use USB Standard for Power USB?

Most USB Mini B Connectors, don't have anything connected to Pin 5. In fact most molded connectors don't have a Solder Wire tag.

For those with some manual dexterity ( to cut open a Molded USB, such that it can Re refitted, and modified), and good at soldering small cables, to tiny pins, read on.....


I bought a USB to Mini 5 pin Cable from CDR King (TM-A506) Php40.

I also bought a small snap off blade knife Php10, and used that to carefully cut off the molder cover/cable strain relief, such that it could be re-fitted and have the cable relief to the left, instead of straight out. Exposing the Pin Connectors is a lot more tricky. I found a Jewelers Screwdriver, useful to pick away at the rubber, bit by bit.

There are 3 soldered Pins along the bottom edge - Black...Green...Red
Above these, between the Green & Red, is the 'White' lead.
To the left of the White is the 5th Pin, with nothing connected to it and nothing to connect to, hardly.

With small needle nosed pliers, you can grab the tiny projection of metal for Pin #5 and gently pull.. Pin #5 should slide out the back.


The advice is to connect a 13.7KOhm Resistor between Pin 5 or 'X' and Pin 4 or GND

Carbon Resistor, 0.25W ,5%, 13k

Crop one lead, close to the Resistor, and 'tin' it! Solder this Resistor end, to the tiny protrusion on the end of Pin5 (or X).
Slide Pin #5, carefully back into USB Min B Body.

The other end of the Resistor lead, you bend back on itself close to the body and below, so it is above and touching Pin 4 (GND), Crop the lead so only a small contact with the tiny solder lug. Carefully solder that Resistor end along with the Black wire, making sure 'no shorts' to Pin 3 (Green).

Time to test with the Garmin Nuvi connected using this modified USB 'A' to Mini USB 'B'

I tried Shorting Pin#5 (X), to Pin#4 (GND) as I did not have a Resistor to start with.

USB ID Volts: 0.00
USB Device: USB-Type A

instead of

USB ID Volts: 1.78
USB Device: Power Cable

That is why I think you do need the 13KOhm 1/4W or 1/8W resistor! (or 18K or 22kOhm)





If I am in the Diagnostic Screen and and using USB Cable into my PC, and it says

Battery: Charging
Batt Current: 25
I Limit: 150mA
USB ID Volts: 2.74
USB Device: USB Type B

If I then unplug the USB Cable from PC and then connect the Mini 'B' USB from the Garmin 12V Power Adapter, it now reads on Diagnostic Screen:-

Battery: Charging
Batt Current: 29
I Limit: 450mA
USB ID Volts: 1.77
USB Device: Power Cable

Clearly the USB ID Voltage has changed, and the Garmin detects this as Power Cable, not USB Type B Data Cable

http://en.wikipedia.org/wiki/USB

In Battery Charging Specification,[40] new powering modes are added to the USB specification. A host or hub Charging Downstream Port can supply a maximum of 1.5 A when communicating at low-bandwidth or full-bandwidth, a maximum of 900 mA when communicating at high-bandwidth, and as much current as the connector will safely handle when no communication is taking place; USB 2.0 standard-A connectors are rated at 1.5 A by default. A Dedicated Charging Port can supply a maximum of 1.8 A of current at 5.25 V. A portable device can draw up to 1.8 A from a Dedicated Charging Port. The Dedicated Charging Port shorts the D+ and D- pins with a resistance of at most 200 Ω. The short disables data transfer, but allows devices to detect the Dedicated Charging Port and allows very simple, high current chargers to be manufactured. The increased current (faster, 9 W charging) happens if both the host/hub and devices implement the new charging specification.