Zumo User Forums

For the Anker stuff you might want to look at this page: https://www.howtogeek.com/769888/what-i ... ry-usb-pd/

It seems to be a little more complicated than just assuming a blue USB port will be sufficient.

Anker mentions "Power Delivery 3.1" which standard allows for the delivery of up to 240 Watts over some USB cables or ports. The max current over USB according to the 3.1 standard seems to be 5 amps. The power increase is obtained by increasing the voltage. The original spec for USB was 0.5 Amps. That limit appears to have been gradually increased to 1.5 amps (about 7.5 watts) without some voltage/amp controlling standard.

You might want to ask Anker for the max current output from their battery banks. It also would be nice to know the XT USB spec.

AugustFalcon wrote: ↑Sat Aug 26, 2023 3:50 pm...You might want to ask Anker for the max current output from their battery banks. It also would be nice to know the XT USB spec.

I am still going back and forth with Anker.

This is what Garmin replied with:

"Hello James,

You will need quite a bit of power. The device needs this type of power:
Input: 10-30V, 1.5A (max)

Output: 4.8-5.5V, 1.5A


Thank you for choosing Garmin,

Lisa
Product Support
Garmin International
For 24-hour access to support videos, manuals, FAQs & more, visit the Support Center."

The XT will work with any of the power banks with a USB port, the question is "How long do you need it to work?"

I've reported my electrical measurements of the XT here before, but I can't find them on this forum. They are also posted at https://www.advrider.com/f/threads/garm ... t-43440432, and support the figure of about 8 watts mentioned earlier. Most of the power seems to be used by the screen backlight.

My son gifted me a couple of these power banks: https://www.amazon.com/Miady-10000mAh-P ... B082PMQWZG.
Capacity: 10000mAh/37Wh (Each)
Dimension: 5.5*2.6*0.6 inches (Each)
Weight: 0.48 lbs (Each)
USB 1 Output: 5V/2.4A
USB 2 Output: 5V/2.4A
Micro USB Input: 5V/2.0A (no output)
USB-C Input: 5V/2.0A (no output)
Recharge Time: 5 Hours (5V/2A plug required)

Curious, I connected my fully charged XT to one of the banks last night and left it turned on, 100% brightness, Bluetooth on but not connected, wi-fi off. Ten hours later, the charge indicators on the bank have dropped only from four to three, and the XT is still showing 100% charge (press and hold the battery icon on the main screen).

Obviously, the XT can be expected to use more power when it is constantly moving, acquiring new satellites and dropping others, calculating new positions and updating the screen, possibly managing music and phone calls, etc., so more tests could be interesting.

My calculations using the 10000mAh number led me to expect about 6.25 hours of charge from this power bank, so I had expected to wake up to a depleted power bank and low battery on the XT. I stopped the experiment because I don't think I will ever use this much capacity.