Normal AC charging a 1490T

While what you are doing may work, I would be concerned that the voltages were not exactly what was required.

Why not just use your USB cable to charge it from your computer?

I agree, voltage is probably an issue. Either just plug in through the computer's USB port, or get an AC-to-Cigarette-Lighter adapter and use the car charger that came with the unit, but in the house.

My 1260T does the same.

If you looked at the specs for both devices, one will have a slight deviation of volts. If you do the math over several hours the device will lack the charging power which will be evident in the slow charge.

I think the issue has something to do with the output in milliamps. If the unit "sees" a lower amount of current (computer usb ports output 5vdc, 500ma) it goes into computer mode. At a higher current it goes into nav mode. Search this site and I'm sure you'll find a more detailed answer. I've seen this topic before but can't find a specific thread on it, though I know it's here somewhere.

Naw, voltage and current is not an issue. USB voltage is 5 volts. While one might be able to find slight variances (in the millivolts) between devices, you could also find that difference between computer USB ports. Since the Garmin is designed to charge from any USB port it will also charge from a powered USB hub or from a cell phone charger that provides the same 5 volt level.

USB is also speced to supply 500ma (max) to the usb device, but this can be less depending on other power demands (an 8 port hub doesn't usually supply 500 ma on each of the 8 ports at the same time for example). It is not a function of current that determines if the nuvi goes into connected or nav mode, as speculated here, since mine goes into connected mode when powered directly from a laptop that can and does supply the full 500 ma @ 5v. It is a function of if the nuvi is talking to a computer or not (also evident because the original poster reports the nuvi at first tries to establish a computer link and then goes into nav mode).

In short the adapter that you are using is every bit as good as charging from a computer or from a much more expensive "official" Garmin device which may turn out to be exactly the same device but with Garmin's name on it. Why fire up a computer just to charge the nuvi when you have a lower power independent charger intended to charge devices? There would be no reason to expect the computer to be any closer to some imagined "ideal" value than the charger. If anything I would expect a device designed to charge to be closer to the idea.

I had a Garmin AC charger and used it on my 760, 855, 885T and c550 and had similar screens with mine that you are seeing. All sounds normal to me.

They all worked fine and the Garmin charger is specially wired to allow you to actually use the unit while charging. The USB cable and other chargers force the unit to go into mass storage mode when you plug them in.

If you look at the spec for any USB device it is going to be 5 volts, period. If you actually measure them it may varry by a millivolt or two but you couldn't accurately predict which would be lower. That does not matter anyway, since the nuvi has to regulate the voltage down to a lower charging voltage for the LiIon battery, it is designed to work just fine on any voltage that you would find on a USB port, slight differences in the output are not a factor.

My nuvi 660 does that also! I wonder if the newer models give an indication when there charging/full.

Yes, and I can do that with the non-Garmin phone charger I am using. The only varient is that first it simulates "mass storage mode", then it comes on by itself, after about 30 seconds, and works fine.

Why not? Although my pc is on frequently, if I am travelling I won't have it with me. And I don't want to have to turn on my pc just to charge the Garmin.

Also, when in "mass storage mode" connected to my pc, the unit screen stays lit.

My phone charger makes the gps start by "simulating" mass storage mode (that is what the screen looks like), then the gps turns on, then I can either use it, or turn it off, and it displays a screen saying it's charging. That screen quickly goes off, while the unit charges.

I put the unit into the car with a phone charger for cigarette lighter to usb device. My 1490 would cycle on and off. Using the charger cable that came with it, then my 1490 works normally.

I thought about getting an AC-to-Cigarette-Lighter adapter, but if my other little charger does the job OK, I don't actually need it.

I'd like a reply from another 1490 user that can tell me if my unit's response to the charger I am using is typical, and/or if they have a Garmin "010-10723-12" Ac charger, and that is what it does, too. But thanks to all for all the replies. - Ted

I have the 1490. I have an ac adapter for a Samsung camera. The adapter has a USB connector as the output. When the 1490 is connected to it, the unit operates exactly as you describe. The adapter says it puts out 4.4V.

Thanks jjen!

I have the AC charger which came with the 660 output
5V-1A. Will this one work with the 1450?

I can't say for sure, but it probably will, since, in this thread and by personal observation my "Motorola" cell phone charger works with the original cell phone, with another brand of cell phone that I have now, with my old Street Pilot c340, and my new nuvi 1490T.

I have a Garmin A/C charger (I can't seem to locate it at the moment though!) and, when I use it with my nüvi 760, the unit goes into charging mode. Period. When I try to use a different charger I get the behavior described above. The Garmin charger is obviously wired differently somehow.

Edit: I seemed to remember something about a different resistor being used in the Garmin charger that puts the unit into charging mode rather than mass storage mode. I did a search and found this thread:
http://www.poi-factory.com/node/17975

as described here:

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