Nuvi and USB (charging low battery)

Thanks for all the responses to my questions.
I don't think I will be spending money for the OEM Garmin charger adapter a will purchase a USB/AC adapter at Walmart (about $10) to use with the USB cable that came with the unit.

is there anyway to change a dead battery yourself. one that will no longer charge?

For about $10 more you can get the Garmin AC adapter and not worry. I am sure there are many adapters out there that will work but the only problem is if one does do something to the unit Garmin will not honor the warranty. Why spend $200 to $300 for a great GPS and not spend an extra $10 (if you can afford it) for one you know will work and not damage the GPS. Personal opinion of course...Besides you will be able to charge the unit without a pc if one is not available.

Actually I own nuvi 650 and when it is connected to cradle and cigarette lighter outlet when you turn power off on unit (using power button) is shows for about 2 seconds "Going to charge mode" and then screen goes blank. If 660 shows similar communicate when turned off when charging it may be the way to check if it's charging or not.

Does anyone know if it is possible to charge, power and use the Garmin Nuvi 865T with the USB connection, in the side of the device itself, while the device is sitting in its cradle? I ask because a USB lead running from a car lighter socket/usb charger adaptor (Motormonkey) is a much less bulky solution than the Garmin cable provided.

Some Nüvi can be used while charging with a USB cable (with some tricks.) But even if that is possible, you would loose the traffic data by not using the "bulky" Garmin cable as that's where the antenna and the receiver for the data is located.

I have a 270 and haven't had any power problems, using either the supplied cord, or Verizon cellphone cords ac/or auto, and have used a euro ac cord in Paris

I'm not an expert on the Nuvi electronics, but I am an electrical engineer. It seems to me to be reasonable that a Nuvi with a completely drained battery may not be able to be charged with the auto adapter. It all depends on how the engineers who developed the battery management system on the circuit board set it up. If the mini USB is the default charging location and the car charger contacts (the ones on the back of the unit) are not the default location, there's probably on-board logic on the circuit board to say "if I see charging voltage on the car charger contacts, switch this transistor to re-route the power to the battery for charging from the car charger contacts" If the battery is COMPLETELY drained, that switch cannot be made. A transistor requires a minimum voltage to be turned on (switched).

Related to this is the topic of depleted battery versus completely drained. The aforementioned battery management systems on modern electronics knows to power the device down and not allow the user to power it on when the battery reaches some critical level. The battery still has enough power to watch the car charger contacts for voltage and switch if needed. That being said, this "watching" for that charging voltage actually draws a little current from the battery constantly. Lithium Ion batteries also discharge on their own over time even if there is no current draw. If the unit is left long enough with a depleted battery, it will eventually become completely drained.

In the case that started this thread, depending on how low the batteries were drained before the unit powered itself off, how long the unit sat after that before the owner tried to charge it, and most importantly, battery age and condition, it's very possible that what he says is true.

Keep in mind again, I have no idea how the Nuvi's are built or how the battery management system is wired or coded, but it is certainly possible in my opinion.

Sorry for the long post - hopefully it clarifies things.

The logical way to do this would be to power the switch from the port where the voltage is applied, not the unit's battery. That is, if there really needs to be a switch. My 750 can be powered by either the cradle, which plugs into the car's cigarette lighter socket or from a USB port. Voltage from the USB port will be 5 volts. The cradle will feed into a 5 volt regulator who's output, along with power from the USB port, can then go through a couple of steering diodes. No switching needed.

Jack j

I find the USB data/charger cord takes a while to charge it. Even with the unit connected and off.

The wall plug in charger seems to work the fastest for me, followed by the car charger.

I forget where I read it but the cradle which is hooked up via the cigarette lighter adapter does not charge the battery. It only conserves the battery by using power from the cigarette lighter rather than the battery. The only way to charge the battery is via the mini USB adapter. I have a cigarette lighter adapter that has a USB port so I can charge the Nuvi in the car (basically a 12V to 5V converter).

My 760 charges while in the cradle. If what you say is true, then everyones battery would go dead in a pretty short time, since the the vast majority of folks never connect to a computer, and the unit does not ship with a separate charging cord.

Besides, actual experience with a C330 and a Nuvi 760 says you are wrong. Both will charge from a completely dead battery to fully charged while in the cradle.

every one of them has info imprinted on it or at least sticker attached check for output data - it says how many volt (V) and amper (A, mA -> 1A=1000mA) device can deliver.

I may have missed something but this is how my 750 works when in the 12v connection (no cigarette lighter). When the connection has power and you shut the nuvi off it says charging... If the nuvi is in normal mode mine still charges but at a slower rate...

I got a Gilsson AC charger that has 5V, 1000 mA output, quite a bit cheaper than the official Garmin one. It does charge fast, usually 2 hours to go from empty to full for a 255W.

It doesn't even have to start off discharged. I have a Nuvi 760 that's only a few months old. I charged mine up fully before putting it in the car, only use it with engine running, and after a month or so it's almost discharged. When I turn the engine off, I'll get a Low Battery warning. Then I have to plug into a USB to charge it up again.

Car adapter voltage is about 12.5V. I would have thought that would be plenty to keep a charge.

Looks like problem with gps battery, charging system in gps or power cable. But because it charge well from usb I will try with last first. Try different power cable and if this will not work just call garmin. Few month old gps still have warranty.

It doesn't make any sens at all. If battery is unable to be charged because it is dead there is no way to charge it. It just doesn't accept and hold any power.

Are you *sure* you are getting a low battery warning when you turn off the ignition and not a notice that it's now running on battery power and will shut itself off in 30 seconds Yes, or No?

It sounds to me like your power socket in the car is switched, meaning that it goes off when you turn off the ignition. Your Nuvi will give a warning at that point and will pop up a notice and ask if you want to keep running on battery or shut down. That's not a "low battery" warning.

A feature of the 760 is if you turn it off while it's in the cradle and still being powered by the car, it does not actually shut off. It enters a sleep mode instead. This is actually kind of cool, because when you come back there is no boot up or acquiring satellite delay. It comes back on instantly.

If it is in sleep mode, it will not warn you when you turn the ignition off and it stops getting power from the car. It will not ask if it should automatically power off in 30 seconds. It will continue to run in sleep mode until the battery runs out.

The best procedure if you intend to leave it in the car in the cradle is to just turn off the ignition and let it power itself off automatically in 30 seconds. Or if you're just running into a store for a minute or pumping gas or something, you can answer No and leave it running.

Now if you are saying the battery meter on the main screen is full and after a period of driving it is showing as less than full charge, you have a bad car charger, dead power socket, or maybe bad contacts in the cradle. Or a last-place possibility is a bad battery that just won't hold a charge.

There are times when I get close to where I am going and know where I am, I turn off my NUVI 350 and it goes into charging mode. The screen goes black, If you touch it, it tells you it is charging.In a short while, it says "Charge complete". When you have it in the cradle in the car, I think it is working off the car system and not off the internal battery.

So the power cord can charge the nuvi unless the battery is completely empty?

If it is empty you need to charge it first w/ usb?

The power cord WILL charge a discharged internal battery on the Nuvi 750. It can also charge it using the USB connection. You don't need the battery suppling power to the unit in order to enable charging. If you needed the battery to supply power in order to charge the unit, you would not be able to operate the unit using the power cord if the battery was bad.

I would also point out that it is almost impossible to completely discharge the internal battery. The unit will turn itself off when the battery reaches the end of it's charge (different from complete discharge). The only way I know of to completely discharge the battery would be to run the unit until the unit shuts off and then put it on a shelf and leave it alone for a few years.

All this assumes that your battery is good.

Jack j

Having run into this charing issue while traveling once and not having an A.C. adaptor or usb charging capability at the time. I'm still at a loss why this has to be so complicated for the end user. Isn't it reasonable to expect the car charger to charge and use a unit no mater what the battery charge level is unless the battery is outside its useful life span?

You might want to go into your system information on your computer and not allow the USB port to shhut down for power saving.

I almost always use my DC car power cord to charge my 660 and have never had an issue, and the battery has been very low (but not dead).

Also read (I believe at the Garmin site) to discharge all the way to prevent memory.

I'll see if I can find that one.

I'm using a generic USB cable that charges it. I thought it was odd that it would when the supplied cable doesn't.

Can't find the other right off.

This is from the regular manual. At least for a Nuvi 2595.

Anyone know if it matters if the unit is on or off?

I guess I should look at the date before I reply. LOL

Necro thread.

Your killing me with that avatar.LOL