Nuvi and external battery pack

[+taylertreasurehunters]

Hi

 

I realise that the "can i use a Nuvi for caching" question has come up a few times so this is one for those who ARE using their Nuvi.

 

I already had a Nuvi when I came across geocaching so havent yet saved up for something that may be more fit for purpose. That said, the main issue I have with it is poor battery life (again well documented in this forum).

 

What I wanted to know is whether these external battery packs can be used to power my Nuvi while it is in use. I know they will charge it but I need 4-5 hours of guaranteed caching so if the Nuvi goes to charging / external drive mode when they are plugged in this would be no use to me.

 

High capacity battery for Nuvi

 

Anyone tried?

 

Thanks

 

Colin

Edited April 21, 2009 by taylertreasurehunters

[+jotne]

It may work.

 

If you connect any USB power on a Nüvi with standard cable, it will go into PC mode and is useless as a navigation device.

 

You need a special cable where one of the wire is connected to ground with a resistor of a specific value. This will make the Nüvi to work as a GPS without going into PC mode.

 

Not sure where you find more info about this (I do not remember where I did read about it). Try google.

[+kallt_kaffe]

If you connect any USB power on a Nüvi with standard cable, it will go into PC mode and is useless as a navigation device.

 

Here's a trick that may work...

 

1. Power on the GPS without USB cable connected.

2. Press and hold the battery meter until it enters "diagnostic mode"

3. Attach USB cable and wait a couple of seconds.

4. Press "Exit"

 

With previous firmwares on my Nüvi 205 pressing exit at this point rebooted the GPS and entered mass storage mode. With my Nüvi 255 at the latest firmware it boots up in navigation mode but powered from USB. You may get different results depending on model and/or firmware.

 

Offtopic: Depending on model this "hack" may also enable you to use the GPS with nRoute. While nRoute finds my 255 in this mode it complains that it does not support PVT. I think it propably depends on what gps chipset is being used. I would not be surprised if the SIRFstar III devices like the Nüvi 200 works with nRoute using this hack.

 

Offtopic2: GSAK actually managed to recieve center point from my 255 in this mode.

Edited April 21, 2009 by kallt_kaffe

[+jotne]

This trick is a work around. Its better to get the correct cable.

 

Here is the the solution. (Found using google)

http://pinouts.ru/GPS/garmin_nuvi_power_pinout.shtml

[+SamSpade47]

This works with a Nuvi 255W.

 

Nav mode while USB cable connected:

 

1. Plug PC or generic AC/USB wall charger cable into the Nuvi255 and wait for it to go into mass storage mode.

2. Slide Power Switch to the right (LOCK Position)

3. Remove the USB plug from UNIT and immediately plug back into the UNIT

4. Slide the Power Switch on the Nuvi to the MIDDLE position.

5. WAIT for it to BOOT UP.

6. After Boots UP it will be in the Navigation mode.

 

Hope this helps.

[+taylertreasurehunters]

Thanks for the ideas guys, I have a Nuvi 360 (I should have said) and I tried both the different sequences that you suggested:

- Going into diagnostic mode didnt help - the moment i plugged in the USB it went to PD mode

- The 360 power switch is just a push on/off type and i wasnt able to do the second option.

 

I will explore leads to see if this yields results! The alternative is to get a second satnav and use the nuvi as a reference for the dowloaded info - a bit of a pain though to carry two satnavs around with me...

 

Thanks for your help

Edited April 21, 2009 by taylertreasurehunters

[+taylertreasurehunters]

I got this off another forum and it appears to work...

 

Try plugging in usb cord and let the unit enter mass-storage mode. Unplug connector and wait for it to start rebooting and then plug the connector back in. Second time, it boots as normal, and charges from USB as well.

 

This works so far on a 350 and 650 hope it will work on others. Hint: The 350 was far more sesitive about when you plug back in. Basically as soon as you see the computer icon on the Nuvi screen disappear--plug back in immediately. If you delay you will be right back in mass storage mode.

 

I'm going to order that battery pack now!

[+jotne]

Best solution is to make the cable described in the link above, then you can just plug it inn, and all should work.

[+taylertreasurehunters]

Best solution is to make the cable described in the link above, then you can just plug it inn, and all should work.

 

You're right it would be a neater solution, what is the best way to short these contacts since i'm not electrical savvy?

 

Thanks

 

Col