Mobius Start-Stop Problem

Sticklebrick

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Milton Keynes
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Dash Cam
Mobius ActionCam
Hi there,

I'm seeing a frequent issue with the auto start feature and wondering if anyone else is seeing the same thing and can help find a solution.

I'm using my Mobius as a dash cam in an Audi diesel with auto start-stop technology (i.e. engine stops when I put it in neutral at the lights). I've got the Mobius wired in to one of the spare fuse slots (an accessory circuit that only comes on when the ignition is on). I have the Mobius 'Power-on auto record' setting set to 'External Only' and the Power-off Disconnect' set to 'Immediate'.

In general the camera starts and stops recording as one would expect when I start and end my journey. However, reviewing footage over the last month I've noticed that a lot of the time (~50%) of the time the camera fails to start recording again after the engine re-starts during an auto start-stop event. This means the camera fails to record large portions of my journeys. The footage of my journey usually ends at a set of traffic lights. :/

The problem, I'm guessing, is that when the car goes into auto-stop mode it cuts the power to the accessory circuits. Because the power is interrupted only for a short duration, this is causing problems for the Mobius camera. Possibly, the camera is still powering off when the power is turned on again and it's therefore not restarting the recording?

I've tried setting the 'Power-off Disconnect' to '10secs' instead of 'Immediate' in the hope that it would just continue to record during the short disruption to the power, but it's not enough. If I stop the engine at the lights it's usually for 5-60 seconds.

What I think might solve the issue, is the ability to specify the 'Power-off Disconnect' period to a couple of mins (say 1,2,5, or 10 mins), this way the camera wouldn't stop recording at all if the power is interrupted for a short period. Or maybe the firmware can be updated so that it correctly restarts recording after a short power disruption? Or maybe I've just got a dodgy camera?

Can anyone help?

Thanks.
 
Can you wire it into an IGN "ON" power source? There are usually two (or more) IGN "ON" circuits and one will have continuous power when the engine is cranking over to start (the other/s will be shut off like the ACC power when the engine is started.) If you can tap your Mobius into the IGN "ON" that isn't cut out that should fix the problem. It will be the circuit that powers things that are vital for the engine to start - like the engine's ECU. ;)
 
Can you wire it into an IGN "ON" power source? There are usually two (or more) IGN "ON" circuits and one will have continuous power when the engine is cranking over to start (the other/s will be shut off like the ACC power when the engine is started.) If you can tap your Mobius into the IGN "ON" that isn't cut out that should fix the problem. It will be the circuit that powers things that are vital for the engine to start - like the engine's ECU. ;)

So what you are saying is that some accessory circuits will be cut briefly when the starter motor is engaged (I guess anything that draws a high current like heaters, AC, etc.), whereas there should be other circuits that stay on. I can't see these identified in the manual, so will have to experiment. I will try the 'Infotainment system' as that doesn't seem to go off.

Still, it would be useful if the Mobius could better deal with a short interruption to power.

Thanks.
 
So what you are saying is that some accessory circuits will be cut briefly when the starter motor is engaged (I guess anything that draws a high current like heaters, AC, etc.), whereas there should be other circuits that stay on. I can't see these identified in the manual, so will have to experiment.

Yes, I that is exactly what he is saying. The ignition switch has several poles (electrical pathways), one that provides power to certain circuits only when you are cranking the engine, another that provides power to certain circuits only with the switch in the "on" or "run" position, and one that has the "start" and "run" positions of the switch physically connected together in the switch so there is power connected to certain circuits both while the ignition switch is in the "start" and "run" positions .

You have to look at a wiring diagram of your car's ignition switch circuits to identify it. You may however be able to locate it by tapping off the fuse labeled as power to the car's computer, also known as the ECU as murcod mentioned.
 
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Thanks Whatatay.

Being equipped with "stop/ start" technology you'll possibly find more suitable power sources than a normal vehicle - like your "Infotainment System" power circuit. (Every vehicle I've owned has cut the power to the audio system when cranking the engine.)
 
Just found this - I'm not sure the OP or responders will still be here, but I've just discovered my mobius is doing the same (mine's using a capacitor), it is definitely a brief cut to power when the car auto starts as I connected an LED into the mobius power source and it went off briefly every time the car auto started.
Tried a blueskysea b1w and that's even worse - for now I'll revert to the mobius and try to remember to disable auto stop until I can get it wired in properly.
 
it is definitely a brief cut to power when the car auto starts
I did post a circuit in another thread that uses a timer and a direct connection to the battery to control the Mobius power. So you use the problematic ignition switched voltage source to trigger the circuit and it overcomes any power spikes on engine start up. I've been using it in one of my cars for a couple of years now. The hard bit was trying to work out something that didn't use any power when the vehicle is off.
 
Wow, that sounds like getting into circuits I'd rather not touch. The easiest solution may just be to connect directly to always on circuit and let it record permanently. I also toyed with the idea of putting a small power pack between, so the car charged the battery pack, and the battery pack ran the camera, which would keep running until the battery pack ran down, but that's adding a battery back in, which defeats the point of the capacitor.
 
The easiest solution may just be to connect directly to always on circuit and let it record permanently.
You'll quickly have car battery issues doing that. Heat parked in Summer may also be an issue and cause a Mobius meltdown. (Yes, it happens!)
 
Yeah, I wondered. Thanks for that. I'll speak to my local garage to see what he says about available wiring options.
 
You'll quickly have car battery issues doing that. Heat parked in Summer may also be an issue and cause a Mobius meltdown. (Yes, it happens!)

Not necessarily. I ran a Mobius 24/7 for a few years in my workvan without issues. Temps here in summer go to 32 (90F) for a couple months each year, sometimes going a bit higher. It does require driving every day to keep the battery above danger level. My old bus has a 80A bgattery, and as best I can figure this scheme reduces it's service live about 20%. About $0.50 US per day is the end cost to me and I'm OK with that.

It's not what I'd call the best approach, maybe not even a good one, but it does work for me.

Phil
 
Could be the cheapest one - a new curcuit board is about £35 :)
 
Not sure how well it would work with start/stop though. Some cams are pretty sensitive about input voltage drops. Here's a simple solution using a small AGM battery instead of any powerrbank solution:
AGM Aux.gif

What happen here is that the relay coil taps into a circuit which is hot only when the engine runs and is charging the car battery. When that activates, the relay closes and charges the AGM battery and powers the cam PS, but when the car stops charging the relay opens and the cam PS now gets power from the AGM battery only. So running or stopped the cam PS is always seeing sufficient power, and is not being subjected to current drops when the car starter is engaged. There is always power to the cam doing this, so the cam will need to be turned on and off and set to parking modes manually.

If you want automatic cam starting/shutdown and parking modes, you need a 3-wire HWK; the wire which goes to "ACC" will need to be tapped into a car circuit which functions with the ignition key, and the wire which goes to "BAT" will go as shown to the + side of the AGM battery. If you're only using the cam while driving a very small AGM will do. If you want to use parking modes you'll need a larger one with the size based on how long you need it to run. The added wiring and relay need to be sized to the same amperage rating as the added AGM battery or more for safety, and fusing inserted as appropriate to protect the car wiring, Other than charging the AGM, the additional load on the car will be only the relay coil which draws very little current so any computer-controlled power scheme or monitoring will probably not be affected at all. The added charging load of the AGM will be similarly minimal and not 'noticed' by the car.

The benefits here are safety- the AGM can tolerate more heat than any Lithium based battery. The AGM operates at car battery voltage so no charging regulation is needed. AGM batteries come in a wide variety of sizes so any reasonable parking time wanted could be accommodated. If a 3-wire HWK is used you will never need to touch the cam to get it's normal functioning. This entire system requires no electrical skills beyong crimping on wire connectors and mounting the AGM securely. The system can be split up and placed wherever you like, as any voltage drop will be insignificant on the 12V side given acdequate wire sizing. The cam PS can be kept close to the cam so the vol;tage drop on the 5V side will not be abnormal.

Phil
 
Thank you, that's very comprehensive, I certainly like the idea of AGM rather than lithium.
 
AGM and SLA are safer, but have their own issues: size, weight, and not being able to discharge as deeply as Li types. These issues are not big ones for most cars; there's almost always a good location somewhere for them. There is one hidden issue here- charging amperage. You will probably have to run the first wire (between car battery and common relay terminal) all the way to the car battery, or to a terminal point downstream of it meant to carry the high-amperage load you'll be adding to it. That will require a large fuse as close to the power take-off point as is practical; you aren't going to find this kind of power at a fusebox so the usual "Add-a-fuse" taps won't work like they do for cams and devices like the Cellink Neo which need less charging current :( You might also need a large "Filter capacitor" there such as car audio systems use if the alternator isn't 'clean' enough, but I don't think this is very likely.

This is essentially the system I'm going to put into my workvan. I've done one very similar to this to provide uninterruptible power to my smaller Ham radios at home, so I know it will work. It can also be done electronically but at higher cost and complexity. As more cars get start/stop technology and computer-controlled/computer-monitored power schemes something like this or the Cellink Neo are going to be more necessary to gain a trouble-free dashcam install with parking modes available to use. It does require some basic DIY skills and some common sense in wire sizing, wire routing, and battery mounting but it's not hard to do with that much going for you ;)

Phil
 
Not sure how well it would work with start/stop though. Some cams are pretty sensitive about input voltage drops. Here's a simple solution using a small AGM battery instead of any powerrbank solution:
.....

Phil

Thanks for all of this - I think I've found an easier solution in this case - spoken to my local friends Audi independent garage and I can have a remap to permanently disable the autostop/start feature on my car, so this issue then simply doesn't happen. hopefully this discussion is useful to those who want to keep the autostop feature.
 
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