How Much Power does your GPS draw?

[FWTBT]

Does anybody know how many amps a Garmin GPS draws. I have the NUVI 2757 LM. It?s the large one with the 7? screen. I can?t find any power draw information from Garmin.

3BR Powersports makes a really nice weather proof USB power port cable. One has a max. power output of 2.1 amps but a no load power draw of 35 milliamps. They claim it will draw down a MC battery in 3 to 5 days and recommend wiring it to a switched outlet. The other cable has a 1.0 amp max. output with a no load power draw of 200 micro amps.

I purchased the cable with the 1.0 amp max. power because I wanted to wire the GPS to a non-switched power supply. I like the idea of controlling power to the unit with the on/off switch and not have it shut down every time I turn the key off.

Now I am wondering if 1.0 amp is going to be enough power. I should have done this research before I purchased cables online. What a PITA it will be to start shipping stuff back and forth.:banghead:

 

[Illinois]

Don't know how much it draws but I woke up to a dead battery once after leaving a Nuvi 500 plugged in over night. Fortunately it was tucked away in the garage.

 

[T_C]

Look on the charger that came with the GPS. See what it is rated at. It should be marked.

If not.... plug it in and try. Start with a full charge GPS, hook it up to the 1 amp charge cord and simulate a route, check it in an hour and see if it is still charged.

 

[Skunkape]

I have been looking in to the same thing. I think I read that the 1 amp model is not enough. I am planning on getting the 2.1. I would be interested in hearing your impression of these.

At this point you could just wire it temporarily and try it.

 

[T_C]

I purchased the cable with the 1.0 amp max. power because I wanted to wire the GPS to a non-switched power supply. I like the idea of controlling power to the unit with the on/off switch and not have it shut down every time I turn the key off.

BTW... if your not familiar with the Garmins, most ask if you want them to shut down when external power is removed. If you want to leave it on for a bit while it runs off the internal battery you can do that.

Only takes once of killing the battery cause you left the GPS on to decide that maybe it should be on a switched power-port.

 

[FWTBT]

Don't know how much it draws but I woke up to a dead battery once after leaving a Nuvi 500 plugged in over night. Fortunately it was tucked away in he garage.

That's the thing with non-switched power, I'll have to remember to switch it off so I don't have a dead battery in the morning.

 

[FWTBT]

BTW... if your not familiar with the Garmins, most ask if you want them to shut down when external power is removed. If you want to leave it on for a bit while it runs off the internal battery you can do that.

Only takes once of killing the battery cause you left the GPS on to decide that maybe it should be on a switched power-port.

Good point, thanks. I had forgotten about that. It brings up a prompt when the power is killed asking if you want the power to remain on.

 

[dduelin]

I was surprised the manual does not give an amp draw in specifications but it's been my experience all my Garmin devices drew / draw less than 1 amp. In the manual it does specify a 1 or 2 amp fuse in the cable so I'm guessing the 1 amp cable would suffice. Just a guess though.

 

[veefore]

My Garmin 3750 works just fine with my oem socket which has a 2amp fuse.

 

[v8-7]

Even when the gps is off, the gps battery discharges causing extra current to keep it charged .
Using a switched 12V supply is easy enough to not have to worry .

I measured a 4.3 inch Tomtom at 4xx ma with the bike off anf and the tomtom on during times of charging and I think 1xx ma draw (130 ish as I recall ) with a "fully " charged although not new gps battery and the tomtom off.

It was posted here somewhere..

 

[Nashcat]

If it helps any, my Zumo 220 has a 1 amp fuse in the power cord, so it can't be drawing much.

John

 

[FWTBT]

Thanks for all of the quick replies everybody. :bow1: Sometimes my brain gets stuck in one direction and other peoples input helps get the creative juices flowing again. I guess that comes with old age.

I'm running the battery in the unit down using a simulated route as I type this. I don't have a garage anymore and I want to keep the wires clean so I've pulled my battery and brought it inside. Once the GPS's internal battery gets nice and low I'll hook it up to my new power port cable and see how it works. I'll let you know.

I'm also starting to second guess myself on whether or not to hook this thing up to a switched or un-switched power source.

 

[T_C]

it's been my experience all my Garmin devices drew / draw less than 1 amp. In the manual it does specify a 1 or 2 amp fuse in the cable so I'm guessing the 1 amp cable would suffice. Just a guess though.

A one amp fuse on the 12v side of the plug does not mean one amp draw on the USB (5v) side. One amp at 12v is 2.4 amp at 5v (assuming no loss / 100% conversion efficiency. ) Cheap style voltage regulator won't do this but better linear models come close.

Just FYI.

 

[FWTBT]

I have been looking in to the same thing. I think I read that the 1 amp model is not enough. I am planning on getting the 2.1. I would be interested in hearing your impression of these.

At this point you could just wire it temporarily and try it.

Here are the results of my test today.

I brought the battery inside and checked it for voltage. It was at 13.05 volts. It?s a new TruGel battery I bought last summer. I ran my internal battery on the GPS down until the low battery warning came on. I set up the GPS to do a long simulated route and set the display brightness to 100% then hooked it up to the battery. The voltage read 12.83 volts and the amperage draw was .52 amps. After 1 hour the internal GPS battery was fully charged and the current draw dropped down to .5 amps. After 6 hours my battery was still at 12.83 amps and the GPS worked flawlessly.

Everything seems to be working fine so I?ll keep the cable and use a non-switched power supply. In retrospect I probably should have gone with the heavier cable and used a switched power supply.

It would be interesting to know why Garmin doesn't provide more details on their spec sheets or on the devices themselves. I thought it was some sort of industry standard to label electric or electronic devices accordingly.

I used a Red Band GPS Power Cable from 3BR Powersports to connect the GPS to the TAPP LITE Power Port. The products appear to be good quality, especially the weather proof connection. I purchased these as well as other items through GPS City and so far they have been really good to deal with.

Once again thanks for the quick input this morning, it helped me get back on track!

 

[Skunkape]

Good to hear. I hope it draws as much in simulated mode as it does navigating. Please keep us up to date once you get it all done. Glad to hear the quality is good. I have been reading good things about them.

 

[FWTBT]

I found some detailed information on my Garmin GPS. I touched and held the battery power level icon on the upper right hand side of the screen and "voila"! This appeared. About half way down on the left side it says "l Limit USB 500mA". I'm not sure what this means but 500mA is .5 Amp, I think? Would this indicate max. power draw? Does anybody have any ideas.

 

[T_C]

Seems to make sense. I is the symbol for current in electrical shorthand.

So it looks like it is limited to drawing .5 amps from the USB or external plugs (if it even has an external plug, many just use the usb port exclusively).

 

[FWTBT]

Seems to make sense. I is the symbol for current in electrical shorthand.

So it looks like it is limited to drawing .5 amps from the USB or external plugs (if it even has an external plug, many just use the usb port exclusively).

Thanks for the reply. I have two ports on the unit. One is a mini USB and the other is a micro USB. The mini is used for connecting to a power source and the micro is used when transferring data. So when I update the data on the unit I use the micro port to connect to the computer. I have also connected the mini to the computer and seem to be able to charge the unit with this connection.