power requirements for Nuvi 660, 760

I'm having trouble with both of our Nuvi units in my car. Both the 660
and 760 fail to charge when connected to my cigarette or power outlet.
The result is the unit dies halfway to my destination with low battery.
I observe the absence of a lightening rod on the battery indicator that
seems to indicate no power (or not enough power) is getting to the
unit.

I have checked the voltage coming out of both outlets and found it to
be identical at 15.35 volts unloaded. I am unable to determine the
amps at these outlets.

I have used each of these uits in my wife's car with no problems. Each
unit has been tested on the wife's car with both power cables, so I
know everything is working correctly (GPS, cable, mount).

Does anyone know the amp requirement to run a 660 or 760 or does onyone
have a suggestion as to what else I need to look at?

On 5 Jul 2011 21:38:33 GMT, John Carter wrote:


They are USB devices, so the most likely current requirement is 500mA,
but 1000mA is possible.

Try a regular automobile USB charger and try the same cable that you
used in the other car.

Make sure the charger you're using makes contact at the bottom of the
car's power socket.

Try another power socket if your vehicle has more than one.

Some devices, some Garmins among them, have USB cables with resistors
connected between the pins to signal the charging mode. Try different
cables.

--
Gene E. Bloch (Stumbling Bloch)

On 05/07/2011 22:38, John Carter wrote:
Check the fuse in the car cigarette lighter circuit.
They are normally 10A of 15A but can blow if a coin falls in, kids have
been playing with it, charger doesn't fit properly or the fuse has been
changed for a lower rated one (say 5A) instead of the higher rated fuse.
The 5A fuse then blows is the cigar/cigarette lighter is plugged in.
DAMHIKOK
Dave
--
Blow my nose to email me

I have done some further testing. I have a USB power adapter that
plugs into the cigarette lighter. Plugging the 660 with its USB
cable into this adapter shows a lightning rod in the battery
indicator, which, seems to indicate the 660 is charging. This also
yields the same result by plugging this same adapter into the aux
power socket ocated next to the cigarette lighter. The same happens
on my wife's car.

lighter. Pluggig the 660's ac charger into this device yields NO
lightening rod in the battery indicator. I get the same result in
the Aux power socket. Plugging the inverter into my wife's car gives
a lightening rod in the battery indicator.

It looks as if my vehicle is not providing enough amps to either the
cigarette lighter or the aux power plug with a device other than the
USB adapter.

I think this is the conclusion from what testing I've done, so I
guess I'll take it in to have a service tech look at it.


By the way, I have checked the fuses and they are good and the proper
values according to the owner's manual.

Thanks to all who respinded.

On 10 Jul 2011 14:19:53 GMT, John Carter wrote:

One more thing to look at is that if you checked these with the engine
off, you may wish to run the tests again with the engine on. A battery
provides a nominal 12V (which usually means 11-12V) while an
alternator and regulator normally provide someplace between 14 and 15
volts. Which means 20% more amps through your fixed load... That might
be enough to change the characteristics somewhat. (Also, next time
you're getting your car serviced, ask 'em to replace the plug jack.
Corrosion in the jack or wiring connecting the jack can cause enough
resistance to drop the current below charging threasholds.)

--
Give a man a fish and you feed him for a day; give him a freshly-charged
Electric Eel and chances are he won't bother you for anything ever
again.
-- Tanuki