Should I Switch From A Garmin Zumo XT To A Zumo XT2 On My E-Bicycle?

[Jim1348]

I currently have a Garmin Zumo XT. I bought it several years ago for ATVing. It works well for that and I use a power cord to the 12 volt outlet.

Three years ago I bought an e-bike. I installed a handlebar mount and use after-market maps that I have added that show bicycle trails. It works well for that, but the internal battery doesn't last very long. As a result, I typically bring along a power bank and a short cord to connect to the Garmin Zumo XT's mini USB port. The problem I have is the mini USB seems to lose connection fairly often. I recently posted hear about that and I gather it is a well known problem. I contacted Garmin and they quoted my $130 to repair the port. What is unclear to me is if they actually replace the Zumo with another one or do they repair the port?

Another thought I had is to switch to a Garmin Zumo XT 2. The battery specifications for the Zumo and Zumo XT2 are different.

Garmin Zumo: Battery life up to 6 hours (up to 3.5 hours at 100% backlight)

Garmin Zumo XT2: Battery life up to 7 hours (up to 5 hours at 100% backlight)

I am sure that I get nowhere near 3.5 hours at 100% backlight on my Garmin Zumo. Of course, the device is several years old, so I don't expect them to last that long.

A typical ride for me on my e-bicycle is 3 hours or less. Is it reasonable to assume that the Garmin Zumo XT2 might last that long on the internal battery?

I might also consider using a battery power bank to extend run time.

It looks like the Garmin Zumo XT2 uses a USB-C port for connecting to a computer for data transfer and charging.

Is the Garmin Zumo XT2 USB-C port more robust than the Garmin Zumo mini USB port?

[smfollen]

I don't think any USB port is designed to be robust. They are intended for charging and connection to a computer. Vibration while riding is likely to degrade any USB port.

The XT wiring harness reduces 12v vehicle power down to 5v (USB voltage) which is delivered to the XT.
The XT2 is designed to receive 12v power from its supplied motorcycle mount.
The XT2 can be charged through its USB C port but it will not charge at all from a typical USB charger while in use. That requires a high power charger - 2.1 amp minimum I think? - so I doubt it would charge from a power bank while in use.

[jfheath]

It is not necessarily the port itself that gets damaged. The port is connected to a circuit board - those things covered with thin copper board which is etched away to form conductive tracks on both sides. It has component soldered onto these tracks top and bottom.

The usb port is bolted through the board to make it sturdy, but it is still a relatively large component soldered to a flimsy copper track. Plug a lead into it and put it onto a back, ride it on a rough track with a power cable attached - it becomes a relatively large component soldered to a flimsy copper track with a relatively heavy lead attached which is flaying back and forth as you ride dirt tracks.

Now - you must have done this at some point. Any metal that you cannot cut or detach from another bit of metal. You bend it one way. Its hard to move. You bend it the other way. It's hard to move, Bend it back, it's a bit easier, back again easier still. Repeat. Eventually it breaks. It is called 'work hardening' - the more you do it, the less flexible the metal becomes. After a couple of attempts, It doesn't bend at all. It cracks and snaps.

Now think about that rapidly flaying cable and what it is doing to the soldered connection on that flimsy circuit board.

Garmin make all sorts of navigation products. I'd have a look and see what is on offer for mountain bikers.

[proofresistant]

Think about the following 1 alternatives:

Keep using the XT but use the original XT mount with the original 12V power supply.
Maybe you can get the Garmin 12 volt power supply cheaply used if you don't have a 2nd.

Then buy a USB to 12 volt adapter.
Connect the USB to 12 volt adapter to the Garmin 12 volt adapter connection and a standard power bank.

81SGhcf-HdL.jpg (449.23 KiB) Viewed 1790 times

I found this on Amazon: https://www.amazon.de/dp/B0DJ5GM725


Advantages:
- There are enough powerful power banks on the market
- Such power banks are “relatively” cheap
- Even if there is a USB plug in the power bank, this plug or the power bank is much easier and cheaper to replace in the event of a defect.


This works quite well for me with the XT2. I use it like this on my second motorcycle, I didn't want to rewire

Think very carefully about the XT2!
For example, the XT2 cannot ride any profiles other than motorcycle.
I think the XT had other profiles with which you could choose what you wanted to ride.

[Jim1348]

...Keep using the XT but use the original XT mount with the original 12V power supply.
Maybe you can get the Garmin 12 volt power supply cheaply used if you don't have a 2nd.

Then buy a USB to 12 volt adapter.
Connect the USB to 12 volt adapter to the Garmin 12 volt adapter connection and a standard power bank...

That is a great idea. I still have the original Garmin Zumo XT mount in my basement.

Using a USB 5V to 12V boost converter is a great solution.

Thank you!

https://www.amazon.com/SinLoon-converte ... hdGY&psc=1

[proofresistant]

Using a USB 5V to 12V boost converter is a great solution.

If you still have a mount it's worth a try.
Let us know here if it works with a Zumo XT (first generation) also.

Keeep in mind,
the adapter mentioned above can probably only supplies 10W, maybe just a little over 9W.
Just over 8 watts seems to be sufficient for my XT2.

[Jim1348]

Perhaps a USB-C 5V to 12V boost converter would be an option, too.

I will see if I can find one of those.

[proofresistant]

Hi @Jim1348 ,
I have thought about my tip again and now have doubts as to whether it was really a good idea for the XT.

It works quite well for the XT2, which I use exactly as I described.

But you are looking for a solution for the zumo XT 1 (first generation)
However, this could be different for the zumo XT 1 (first generation).

1.
It may be that the additional original Garmin 12 volt to XT converter itself requires too much additional power, so that the 9-10 watts of the adapter are not enough.
With such a solution a test is necessary.

2.
Maybe you don't need an adapter solution at all.
My consideration, but only just theorizing:
2 a) It may be, I am not an electronics engineer, that the standard USB A output of a power bank always supplies just 5 volts.
2 b) It is also possible that the pins on the zumo XT holder also require such 5 volts.
2 Conclusion)
If these two assumptions correspond to reality, then no converters would be required at all.
Then it could be enough to take an old USB A cable, cut off the plug, and take an old Garmin zumo XT mount and cut off the cable to the adapter and connect both together.

But these are just my thoughts, ask an electronics engineer or specialist!

[jfheath]

The Zumo XT2 runs on 5v from the USB cable - not 12V. The unit itself operates at 3.4 volts - according to the battery screen.

There is a lot of hype about the 12v / 5v power between the XT1 and XT2.

The XT1 runs on 5v - connected to the bike's 12v battery by a power cable with an in-line transformer, whic reduces it to ~5v.
The XT2 runs on 12v - direct to the XT2 cradle - which has an additional 12V pin - the top one of a column of 6 on the rear of the XT2 and the top pin in the cradle. But the XT2 unit also operates at around 3.4v - so it must have an internal transformer.

However - the XT2 will also run on the 5v provided by the XT1 cradle. The XT2 is designed to be able to fit in the XT1 cradle and to use the 5v power supply provided. The XT1 has 5 pins, one of which (3rd from the bottom) supplies 5V.
I often forget that mine is still in the cradle and is left on all day - fully charged running on a 5v supply to the XT1 cradle.

When plugged in to a USB power outlet - the XT2 says that it is not charging and on the battery screen shows a limit of 500mA
Like phones - the XT2 can be used while it is plugged in to a charger - topping up and draining at the same time. So this likely means that it is discharging faster than the power topping up. But I can see no evidence that is what is happening on the battery screen of the XT2.

When I plugged in a charger pack - about the same size as a slim mobile phone - the XT2 battery screen showed USBC Hi Power and a USB Limit of 2,500mA and the battery voltage showed a steady current of 300+mA going into it. The battery indicator in the top right corner of the main screen said that the XT2 was charging

The XT1 when plugged into a wall socket and showing the battery status screen shows a battery current of between 1 and 60mA going into the battery. So charging, but very slowly. That's OK - it is not running down. When in the XT1 cradle it is showing 346mA charge.

The power pack will deliver 2.4A from it's USB A socket. That shows a flow of 180mA to the XT1

You can get very small lead acid batteries that supply 12v. 0.8Ah typically. The radio controlled model people use them. I cannot see how much the XT1 uses to work out how long that will last.

But all of that musing still leaves the issue of a lead flapping around and slowly loosening the connection to the circuit board.

So I'm just simulating a route on the XT2 with no power. See how long it lasts before running out of battery. Screen at 100% brightness, no time out set.
07:00 - Started simulating a route to N Coast of Scotland. Battery almost full.
09:06 : Battery at 3/4 full
10:42 Battery showed 1/4 full
11:02 Battery showed narrowed red segment
11:06 Screen dimmed to 40% to conserve power
12:25 Still going - albeit on 40% screen brightness.
12:38 Dead.

So that's 5 and a half hours running a simulated route, 4 hours of which were at full brightness.

I plugged it into the power pack and turned the screen off - so that it said 'Charging' (etc) on a black screen.
At 13:39 the battery showed half full, green.

Footnote: So why does the XT2 have a 12v supply to the cradle rather than 5v.

I think that the answer is to do with the amount of power the main lead is likely to require from the battery. The XT2 supports group radio, handlebar controller and potentially other devices that can be piggy backed onto the main power lead using Garmin's ever-so-expensive 'Y' adaptors.
They may need 12v to operate - but carrying power for a large number of devices at 5v will require 2.4 times the current that it would require if 12v is used. So running it at 5v would require signicantly thicker cables.

Eg using headlight bulbs which require 60 watts of power.

60watts at 12v = 5 Amps. (Watts = volts x amps)
60 watts a 5v = 12 amps

The cable diameter would need to be doubled (approx) to cope with the extra current required to provide the same power at 5v
As it is, the 12v cable is quite hefty.

[proofresistant]

The Zumo XT2 runs on 5v from the USB cable - not 12V.

The USB ports are not designed for rough use. There is a risk that the sockets will be damaged. This was exactly the problem of @Jim1348, he was looking for an alternative, and with the XT2 the use of the 12V standard zumo mount adapter is a good alternative. For the XT (1), however, this may not be such a good idea.

The unit itself operates at 3.4 volts - according to the battery screen.

The battery has the shown 3.4 volts, but this is more or less not important, because the zumo device internally makes what it really needs for the work on volts.

When plugged in to a USB power outlet - the XT2 says that it is not charging and on the battery screen shows a limit of 500mA

The maximum 500mA is completely dependent on what the USB port supplies. The maximum varies depending on the PC connection. Only the old USB A standards are limited to “only” 500mA. Newer ones can deliver more!
I use a USB C cable for the PC zumo XT2 connection. And in my setup the zumo XT2 is also charged during this use (Same PC, same zumo XT2 but different USB A port and it won't charge)