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DIN Power Outlets - Canbus switching criteria?

1K views 12 replies 6 participants last post by  TouringTim 
#1 ·
I'm preparing for the arrival of my MY2022 K1600GT to which I will be fitting a Zumo XT for navigation duties (don't bother asking why, that's for another thread). Although I still have a Hex ezCan under my workbench from my last bike, it's overkill for this application so I will be tapping into the upper DIN power outlet to provide power to the Zumo mount.

Does anyone know what the criteria are that the bike uses to cut power to the DIN power outlets after ignition switch-off? My experimentation so far has shown that:
  1. With nothing connected to the socket, it remains hot for roughly 50 seconds after ignition off, then goes dead
  2. With the Zumo power lead connected to it (but no Zumo in the mount) it remains hot for roughly 50 - 60 seconds after ignition off, then goes dead
  3. With the Zumo power lead connected to it and the Zumo in the mount, it remains hot for at least 2 - 3 minutes after ignition off. I got bored waiting, so it may stay hot until the battery goes flat for all I know
  4. With the Zumo power lead connected to it and the Zumo in the mount, shortly after ignition off and while the outlet socket was still hot, I removed the Zumo from the mount and it continued to remain hot for at least 2 - 3 minutes. Again, I got bored waiting, so it may stay hot until the battery goes flat for all I know
  5. While the outlet was still hot after step #4, with the Zumo still out of the mount I cycled the ignition on/off again and it remained hot for roughly 50 - 60 seconds after the second ignition off, then goes dead (like in step #2)
So it appears that in the event the canbus detects zero or near zero current draw from the socket(s) when the ignition is turned off then it cuts the power after roughly 50 - 60 seconds. However, if there is a higher current draw from the socket(s) when the ignition is turned off then it continues to supply power to the socket for some indeterminate time. Does anyone know how long it takes in those circumstances for the power to be cut, or does the socket stay hot until the current drain causes the battery to go flat?
 
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#2 · (Edited)
On my TomTom connected to the dashboard socket, it will only stay on if the battery needs charging. We did this test with another forum member a while ago.

So if your Zumo is fully charged and not drawing a significant amount of power, then it should go off after a minute, which should be standard behaviour after a ride.

If your Zumo has not got a full battery, then it will stay alive until the battery is charged and it's not drawing any significant power.

I have gone back into the garage and seen my TomTom still alive and charging an hour after I parked the bike up, so I'm assuming there is no timeout. However given the Zumo battery is considerably smaller than the bike battery, I don't think you'll have problem.
If you are concerned, I can recommend one of these - Halfords Advanced Lithium Jump Starter - Up to 3L | Halfords UK. They are quite small, handy for charging phones etc on the move, and will get you out of trouble if you have a flat battery. Annoyingly, you can't run an air pump off one directly.

Joe


PS - the manual says that if battery voltage is low, they will switch off, and unhelpfully the manual says:
If the ignition is then switched off, sockets are also switched off in the event of high loads. In the event of lower loads, the sockets remain in operation for some time.

So I guess if you have a really high load or really low load, the sockets will switch off with the ignition, but something in the middle will be on for "some time"
 
#3 ·
Hi Joe,

I'd started to think that I'd managed to ask the question about which no-one knew anything, so thanks for your response.
but something in the middle will be on for "some time"
That's the bit I'm trying to quantify. The odd situation was my test #4:
4. With the Zumo power lead connected to it and the Zumo in the mount, shortly after ignition off and while the outlet socket was still hot, I removed the Zumo from the mount and it continued to remain hot for at least 2 - 3 minutes. Again, I got bored waiting, so it may stay hot until the battery goes flat for all I know
This sort of suggests that the control logic evaluates the current draw at the point the ignition is switched off, and then ignores the subsequent reduced draw (when I removed the Zumo from the mount). It is also representative of the most common use case: Zumo in the cradle, complete the ride, ignition off, then remove the Zumo from the cradle.

I'm not actually concerned about the socket remaining hot while the Zumo is connected, as I would always remove it from the mount when parked up. Rather, I'm interested in how long the sockets will remain hot after I've switched off the ignition and removed the Zumo. The Zumo has an inline 12v to 5v power supply which draws a small current even when the Zumo isn't in the mount, so if the socket remains live indefinitely then there will continue to be a drain which is unhelpful.
 
#4 ·
There are some 12V to USB converters that keep the Canbus alive even w/o anything connected to them. I would observe the power draw for at least 15 min and if it stays on that long, it is safe to assume that you will have a dead bike next morning.
 
#5 ·
I would observe the power draw for at least 15 min and if it stays on that long, it is safe to assume that you will have a dead bike next morning.
That was my concern, so after posting this:
The Zumo has an inline 12v to 5v power supply which draws a small current even when the Zumo isn't in the mount, so if the socket remains live indefinitely then there will continue to be a drain which is unhelpful.
My curiosity got the better of me and I decided to check what the parasitic draw of the Zumo XT inline 12v to 5v power supply is with no Zumo in the mount.

With the aid of my trusty Fluke 175 I first determined that with the Zumo XT (with an almost 100% charge) in the mount, the current draw stabilises to 0.67 Amps. This would obviously be a significant drain that would cause the battery to go flat if the ignition was switched off and the Zumo remained in the mount. Without the Zumo in the mount, the small current drawn by the inline 12v to 5v power supply turns out to be (drum roll...) 0.15mA or 150µA.

That level of parasitic drain is so tiny that it will have no measurable effect on the battery's charge, even after several days. It's certainly at least an order of magnitude smaller than that from the bike's factory-fit alarm system, so I'm no longer concerned that it will cause an issue other than the potential to hold the power sockets live. Unless I were to leave something else plugged in to one of the power outlets as well after ignition off, I don't foresee a problem.
 
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#6 ·
Just thinking aloud here... The only other thing you could do is insert a relay into the XT power connection triggered by a switched 12v supply, maybe from something like the number plate light (or similar) That way you would know that the supply would be cut form the XT once the number plate light goes out after any delay. That could be overkill. There maybe other more elegant solutions if you still want to positively isolate the XT supply with no ignition on.

Having said all that if you are mounting the XT externally its no great effort to just remove it from the bike after use I guess. The only place I can think you might want to leave it in situ is in your own garage.

Thinking aloud....... complete!!
 
#7 ·
The only other thing you could do is insert a relay into the XT power connection triggered by a switched 12v supply, maybe from something like the number plate light (or similar) That way you would know that the supply would be cut form the XT once the number plate light goes out after any delay. That could be overkill.
As I said in my opening post, I still have a Hex ezCan under my workbench from my last bike, but it's overkill for this application. The XT is going to be on one of these mounts, so it is "in the open" rather than being secured:



So I will be in the habit of removing it when I stop anywhere, anyway. And if I'm sat on the bike with the ignition off I can always prod the power switch on the back of the XT to shut it off.

Had I found the parasitic draw of the powered mount to be (say) 2 or 3mA then I'd consider putting in an isolation switch - whether that be by way of an ignition-controlled relay or a simple manual toggle - but having tested and found the current draw to be so miniscule, I'm no longer concerned.
 
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#8 ·
I will be fitting a Zumo XT for navigation duties
Are you planning to also use your phone? Nectar you could power the zumo from the USBC in the phone compartment. I have a cable that brings the power out of that compartment into my cockpit bag. I don't open the compartment anymore.

Maybe you can do the same and keep the powerlet socket free?
 
#10 ·
If you do that with a standard USB port, brightness is limited on the Nav5/6. Looks like power draw limiter activity.
easy to test with a usb c connector.
 
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#11 ·
If you do that with a standard USB port, brightness is limited on the Nav5/6
The XT requires 5v power to its terminals, so that would mean butchering either the standard motorcycle power cable or the car cable and splicing the device end to a USB-C plug.

The Nav V/VI would be more difficult if it too requires 5v on its terminals as the voltage reduction is in the mount, rather than being a separate inline device in the cable.
 
#13 ·
I'm not completely convinced another nav unit is needed on the 22s. Ok the app is irritating, sometimes the WiFi doesn't connect so you don't get the map picture.

But this seems to be a couple of reasons

1. Your phone is still connected to another WiFi
2. Sometimes you just have to turn the bike on and off to get the WiFi to reconnect.

Even without WiFi the Bluetooth connection is far more consistent and you get turn by turn instructions over Bluetooth.

Having travelled a large amount of Europe with the app, I can see improvements would be good but nothing says invest effort with an alternative.

Just don't use that compartment for your phone is the most useful bit of advice I would give.

Also the GS and RT guys on my current tour have been using this app for a while and they're all happy with mapping out a route on that app for us all to follow. So I guess that feature must be quite mature
 
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