XT charging & 40% brightness issues

[DougJustDoug]

Warning: XT newbie question ahead. I haven't yet had the opportunity to wire it up to the bike, so I've been powering my XT thru its USB port with an Anker brand power bank and Garmin's provided USB cable. With screen on 100% brightness with no timeout set, WiFi and BT off, and no navigation running (so basically just using it as a scrolling map), everything was fine; it seemed that the power bank plus starting out with the XT fully charged would keep it going as long as I wanted to ride. However, I downloaded a firmware update last week, and now the XT will only go about 2 hours (with the same settings mentioned above) before it goes into a totally useless 40% brightness mode, even though the power bank is still nearly at its full capacity. Also, when I charge the unit at home plugged into AC outlet using Garmin's USB cable and and several different charging blocks, it will only charge to about 85% capacity (per the "secret" diagnostics screen I learned about here) even if left charging overnight. As far as I can tell, it charges up to that 85% point normally, then stalls out. Software issue related to the update? Is there a way to reboot/reset/power cycle/whatever that could help? I've tried shutting it all the way down and then powering back up, several times, to no avail. I know: wire the damn thing up to the bike's battery like Garmin wants me to do, but still I'd like to figure out what's up. (GPScity.com sells an XT package that includes a power bank so I can't be the only one running it that way.) Thanks in advance.

[jfheath]

Welcome to the forum !

What capacity is the charger that you are using ?

I tend to plug mine direct into a wall socket with a built in 2.1 amp USB charger. Although my Garmin charger (which I think came with my 550) is a 1A charger and that seems to work just fine.

Garmin warns that using some 3rd party chargers will take significantly longer to fully charge the battery. Maybe the upgrade to the firmware was coincidental. I've had no problems with the latest firmware update 6.40.

[HarveyM]

I wouldn't use the Zumo's usb port on the motorcycle (if that's what you're doing).
Doing that can break the Zumo's usb port.
In the car I've found a 2.1 amp usb adaptor or a garmin 12 volt to usb cable (like a Nuvi cable) works.

[Stu]

I have seen somewhere that you need a 2amp charger for the zumo!

Personally I don't think the power bank is supplying enough charge to keep it running and charge at the same time.

I would get it plumbed in with the correct wiring and permanent power from the bike and see how it is

[DougJustDoug]

My power bank has 2.4 amp output. It appears on the face of things that the XT isn't pulling from the power bank (even though the battery icon shows it's charging). I assumed that as the XT's internal battery discharged, it would draw power from the power bank. I'm no electrician, so perhaps that's not how it works?

I finally got the XT to charge to 100% on an AC charger by keeping the unit in standby mode instead of shutting it all the way down.

[lkraus]

The power requirements are definitely confusing. I recently posted this about a similar question on another forum:

In December, my new Zumo XT arrived with a nearly dead battery. It would start to boot up, then shut down.
I tried connecting a 2 Amp phone charger to the USB port and the boot progress bar got to about 10% before blanking out.
It was too cold to ride, or work in the garage, so I connected the motorcycle mount to a 13.6 V, 4 A regulated power supply. The XT booted right up.
My guess was that the phone charger just didn't provide enough power.

But...
I had an ammeter inline at the power supply and found it was providing only 420 mA at 13.6 V, at the default 20% screen brightness. That's less than 6 watts, and includes any power lost in the conversion to the 5 V USB voltage. A 5V phone charger rated at 2 A should provide something close to 10 watts.

I also found that even at full brightness the current was only 580mA, for a power draw of less than 8 watts.
So why wasn't the 2.0 A phone charger strong enough to start the dead XT???

[rbentnail]

I also found that even at full brightness the current was only 580mA, for a power draw of less than 8 watts.
So why wasn't the 2.0 A phone charger strong enough to start the dead XT???

I don't know but I found the same thing, sort of. My XT arrived with a dead battery as well but my laptop usb ports wouldn't charge it. Nor would an older wall charger. When I used an Android phone "Turbo Charger" the XT lit up like a puppy. I figured it had something to do with usb3.0 vs older stuff. It's been working fine charging from my laptop since so maybe it was just when the battery was so low.

[JTLiphardt]

I did some basic testing on a Zumo XT powered by a programmable power supply with constant current / constant voltage. When the unit is depleted and the screen is on full brightness, it can draw as much at 9.2 W, depending on precisely what it is doing (WiFi radio on off; Bluetooth radio on/off; GPS state), which exceeds even a "full" USB (1.5A at 5V = 7W). Interestingly, its power draw varies quite a bit especially in the first few seconds, presumably as the internal power/charging system does a basic check of the power supply and the current it can provide.

The unit will wake up even when connected to an anemic power supply (5V, 0.5A max current) but will not change, and intermediate values (5V, 1.0A max current) lead to in-between behaviors - brief charging, charging then no charging, etc. In terms of power supplies, even when it says it can do 2A, sometimes that is simply false, or, entails a severe voltage drop (5V @ 2A theory; 4.2V @ 2A actual performance) which then creates other problems (low voltage).

So if you are have any sort of erratic behavior with the XT, you are almost certainly dealing with a power supply that that cannot stably provide the needed 9+ W to the device in all device states (brightness, wifi, bluetooth, charging, GPS). The solution is to tap into the 12V power rail and use a 12V->5V converter that can provide at least 5V/1.5A (better yet 5V/2.0A) with no appreciable voltage drop.

[Stu]

I did some basic testing on a Zumo XT powered by a programmable power supply with constant current / constant voltage. When the unit is depleted and the screen is on full brightness, it can draw as much at 9.2 W, depending on precisely what it is doing (WiFi radio on off; Bluetooth radio on/off; GPS state), which exceeds even a "full" USB (1.5A at 5V = 7W). Interestingly, its power draw varies quite a bit especially in the first few seconds, presumably as the internal power/charging system does a basic check of the power supply and the current it can provide.

The unit will wake up even when connected to an anemic power supply (5V, 0.5A max current) but will not change, and intermediate values (5V, 1.0A max current) lead to in-between behaviors - brief charging, charging then no charging, etc. In terms of power supplies, even when it says it can do 2A, sometimes that is simply false, or, entails a severe voltage drop (5V @ 2A theory; 4.2V @ 2A actual performance) which then creates other problems (low voltage).

So if you are have any sort of erratic behavior with the XT, you are almost certainly dealing with a power supply that that cannot stably provide the needed 9+ W to the device in all device states (brightness, wifi, bluetooth, charging, GPS). The solution is to tap into the 12V power rail and use a 12V->5V converter that can provide at least 5V/1.5A (better yet 5V/2.0A) with no appreciable voltage drop.

Thats interesting to know after the issues I had with this mount for my bike and XT

viewtopic.php?t=1318

[DougJustDoug]

For historical purposes, I've since installed an OEM-optional 12V outlet in my bike's dashboard, switched by the ignition thru a relay. I've since been using that outlet to power my XT via a flush-mount dual USB adapter plug, using a coiled USB power cord with 90-degree plugs on each end. I've ridden about 3K miles so far with that set-up without any issues, with the display on all the time and at 80-100% brightness. I'm a road-only rider, and the XT sits on an SW-Motech vibe-dampened mount centered behind a large aftermarket windscreen; I've observed no stress on either end of the USB cable from bumps or wind. I know it's not a water-proof set-up, but I've ridden in maybe 300 miles of good rain so far with no ill effects, though I'm keeping a close eye on things and may try to find some "water-resistant" options. I do have a silicone dummy plug in the unused port on the USB adapter plug to help keep water out.

2/23/2023 update: The set-up described above is still working just fine, even in a fair amount of rain. Unit stays charged while in Nav mode and screen always set between 80-100% depending on conditions.