Mobius Super Capacitor.

Lola said:
Do you leave everything on the breadboard as a finished product for connection in your vehicle? This is all new to me.
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Obviously no. 😉 The breadboard was for testing the circuit only. The "Proto boards" from Adafruit are actually solder PCBs made to the same form/function and to look like common breadboards so one can use the same layout and wiring scheme if desired. Not a bad product for one-of assemblies.
 
Hi guys,
I was wondering how changing the battery to a super capacitor affects the current flow of the mobius in the moment of "turn on". The problem is that I have to connect it to a wire with a relative small diameter (0.35) and since there are some other small consumers attachted to that wire I do not want to risk to blow the fuse (5A) on start up.
 
Update. I installed capacitors in my two Mobius cams 4 years 0 months & 3 years 9 months ago, respectively. Both cams start recording when the engine is started. Both hold date & time correctly, & save the last file after the engine is switched off.
 
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Ermo said:
Hi guys,
I was wondering how changing the battery to a super capacitor affects the current flow of the mobius in the moment of "turn on". The problem is that I have to connect it to a wire with a relative small diameter (0.35) and since there are some other small consumers attachted to that wire I do not want to risk to blow the fuse (5A) on start up.
Click to expand...

The Mobius has an internal charge controller that will limit current to a safe value. On mine, I measured charging current to not exceed 450 mA either with the stock battery or supercap.

In your case, there's no risk to blow the fuse. On the other hand, due to the very small wire diameter you are using (about 28 gauge), there may be substantial voltage drop which can cause instabilities in running the Mobius with the capacitor.
 
Here's a way to "top off" the supercap so that the real time clock can be maintained for longer, though I have not yet tested how much extra time it buys you. This is useful if you plan on leaving your car idle for more than a week. I am assuming that you have access to the camera buttons.

1) After you park the car, keep the engine running.
2) Manually stop recording on Mobius.
3) Once the file has been saved, turn off Mobius.
4) Wait for a few seconds (may be 10 sec?) and the green "charging" LED will come on.
5) When the supercap is fully charged, the green light will turn off. Should take less than 30 sec.
6) Turn off car. 🙂

The theory here is that by saving the file when under power, the charge on the supercap will not be reduced and hence, there will be more left to power the real time clock. Obviously, if you are driving the car often, don't bother with this.
 
Radius8 said:
Here's a way to "top off" the supercap so that the real time clock can be maintained for longer, though I have not yet tested how much extra time it buys you. This is useful if you plan on leaving your car idle for more than a week. I am assuming that you have access to the camera buttons.

1) After you park the car, keep the engine running.
2) Manually stop recording on Mobius.
3) Once the file has been saved, turn off Mobius.
4) Wait for a few seconds (may be 10 sec?) and the green "charging" LED will come on.
5) When the supercap is fully charged, the green light will turn off. Should take less than 30 sec.
6) Turn off car. 🙂

The theory here is that by saving the file when under power, the charge on the supercap will not be reduced and hence, there will be more left to power the real time clock. Obviously, if you are driving the car often, don't bother with this.
Click to expand...

😊 All these work arounds to try and get the Mobius functioning as a reliable dash cam. It's much easier to just buy a dedicated dash cam- particularly now the prices have dropped. (I went with the Mobius 4 odd years ago.)

I made up that "delay off" circuit I previously posted (the one with no current drain when the circuit is idle) and installed it in my car. Afterwards I was thinking I should have also left the "delay on" circuit installed - just to be certain the Mobius isn't ever caught out missing a restart when saving files!

Ebay timer circuit modified- some links soldered to the bottom of the board; the capacitor, diode and resistor glued to the timer module; smaller relay used in order to fit it all into a compact box.
delay%20on%20no%20idle%20current.JPG


Everything squeezed into the box
delay%20on%20no%20idle%20current1.JPG


Circuit layout (from previous page of thread)

Delay%20off%20timer%20with%20nil%20parasitic%20current1.jpg


Using this timer https://www.ebay.com.au/itm/332363552335
 
A lot is about how you use something versus what it is. My cap-equipped Mobius is, within it's hardware limitations, is about as good as dashcams get- utterly reliable in some very tough conditions. What more can any dashcam do than that? 😎

I simply applied the same strategy I use for crew leadership in my work: You go with whatever works best whether you like it or not because only the results matter. There's no need for most folks to turn their Mobius off as the average car battery can easily run it overnight with little or no reduction of life of the car battery. Most can do a who;le weekend with no problems. Used this way you have no start-up problems because you're not re-starting the cam. Current draw remains minimal as the caps stay charged so you're only powering the recording parts of the cam- my caps work just the same as when I installed them over 3 years ago so no complaint there. Card life will be shorter but cards, like my sawblades, are expendable and again the overall cost is minimal. I'm still using a 64GB card which is 3 1/2 to 4 years old at this point and it always tests 100% so far. That's under $0.03 per day so you can hardly complain about any added cost. I see months of summer heat here with highs ranging from 34C-38C (90F-98F) with Mobius recording in a closed work van often parked in the full sun and I've never had a heat problem. The worst I experience is the clock wandering a few minutes per month which is easily dealt with by bringing the whole cam in when I do a card check and running msetup while it's here on the desk.

I do like the delay circuits and the various power schemes folks have devised here- they can be useful and some are admirable designs 👍 But IMHO most folks can do equally well without them by simply going with the flow instead of swimming into the current, and there's no more cost or effort doing it this way instead 🙂 The end results are the same- you get the vids you want reliably- so really; what's there to complain about? After using the same approach with the same results on my WR-1 and B1W I'm beginning to believe that the good dashcams, like computers, do best with minimal instead of constant rebooting, and probably for the same reasons.

Phil
 
I posted the circuit and details because lets face facts- there are a lot of people who post on here suffering with issues when starting their engine and the Mobius just dies. Providing they can find a permanent 12V supply (ie. direct to the battery would be best- where there's less likelihood of surges with engine cranking) that circuit should fix the problem. (I say should because I've learnt the Mobius can be a tricky device. Just when you think you've got it beaten it will throw another variable at you.) With the diagram you can leave off the additional components I added if the 24/7current drain doesn't bother you.

I've had a Mobius melt that was turned off in a closed vehicle, so I've got no intention of trying 24/7 operation. We're in the final month of Summer and have had up to 44C ambient temps, I'd hate to think how hot it would be for a camera inside a locked vehicle. You also mention a van- so I'm guessing you've probably been able to mount the Mobius out of direct sun?
 
In my case, Mobius offers what other cams cannot, that is a very discrete form factor and just the right lens (most others are too wide) for my needs. And as SawMaster said, these proven little wonder cams just work and very well at that.
My Mobi are installed in my "fun" car that is not driven daily (may be even several weeks between drives), so it does not make sense for me to have them continuously powered to record my private garage🙂. I just recently switched to supercaps after ~2+ years on the stock batteries which were getting a little puffed up.

While, I have not had issues with Mobius startups, coming up with these circuits is 1/2 the fun 😛.
 
@murcod, would be interesting to record the temperature inside the car in your area. 🙂. Most of us that live in "temperate" climate locations probably don't realize how hot inside a car can get (I am guessing oven temps range).

Another thing to consider is the quality and range of the Dc-DC converter used to power Mobius. I bought a high quality ones that operates between 7 to 36V capable of 5V @1.5A and mounted it within 20 cm of my cameras. This has proven to deliver very stable power and I've had no problems with Mobius locking up/not recording etc... It may be possible that many problems that people have experienced stem from poor power delivery caused by bad supply connections, bad grounds, too long cables causing excessive voltage drop and such.

ps: electronics come in "automotive" grade which mean the components are certified to operate under automotive relevant voltages and temperature ranges. Don't know if the cheap ebay boards use such components (which are more expensive) so one should exercise some caution so the car doesn't burn down😉.
 
Yes, it's out of the direct sun as I've discovered that no cam does well unshielded in the direct sun here. And the temps are high in my closed van with it's huge surface area. On the worst days the air temps inside are so bad you have to open the door(s) and wait a bit so that the air inside cools to a more breathable level 😱 My educated guess is that at times the ambient temps in my van sometimes reach 65C (150F) or more. Anything receiving the direct UV from that kind of sunlight will of course be much, much hotter which is why folks here so love our shade trees 😍 My car installs had the advantage of factory tinted glass which my van doesn't have, and in them some cams can take it and some can't, but none have ever melted. And maybe part of my success lies with the Anker PS I use; the two-piece 4M cables between it and the cam can't be helping there 😛

My point is that there may be other approaches available to people having start-up issues, perhaps unplugging the cam when the car will be unused like on the weekend, but leaving it running through the week otherwise. It's probably not going to hurt anything doing that based on my own experience. Fully automatic operation is indeed nice but it's not necessary to limit yoursef to one extreme or the other- there is middle ground to work within so you're not constantly plugging and unplugging your cam 😉

I'd hoped to see some thoughts from others regards my theory of how the usual numerous boot cycles might affect cam reliability or longevity 🙂 As most electronics buffs know, component failure occurs more often at start-up than at almost all other times put together so I do wonder if my thoughts on this are as valid as they seem to be!

Phil
 
SawMaster said:
I'd hoped to see some thoughts from others regards my theory of how the usual numerous boot cycles might affect cam reliability or longevity 🙂 As most electronics buffs know, component failure occurs more often at start-up than at almost all other times put together so I do wonder if my thoughts on this are as valid as they seem to be!
Click to expand...

The Mobius cams in my vehicle experience several boot cycles per day and have been in service for several years now in every imaginable temperature extreme. There has been no evidence of any adverse effect to date on either the cameras or the memory cards.
 
Update. I installed capacitors in my two Mobius cams 4 years 1 month & 3 years 10 months ago, respectively. Both cams start recording when the engine is started. Both hold date & time correctly, & save the last file after the engine is switched off.
 
murcod said:
😊 All these work arounds to try and get the Mobius functioning as a reliable dash cam. It's much easier to just buy a dedicated dash cam- particularly now the prices have dropped. (I went with the Mobius 4 odd years ago.)

I made up that "delay off" circuit I previously posted (the one with no current drain when the circuit is idle) and installed it in my car. Afterwards I was thinking I should have also left the "delay on" circuit installed - just to be certain the Mobius isn't ever caught out missing a restart when saving files!

Ebay timer circuit modified- some links soldered to the bottom of the board; the capacitor, diode and resistor glued to the timer module; smaller relay used in order to fit it all into a compact box.
delay%20on%20no%20idle%20current.JPG


Everything squeezed into the box
delay%20on%20no%20idle%20current1.JPG


Circuit layout (from previous page of thread)

Delay%20off%20timer%20with%20nil%20parasitic%20current1.jpg


Using this timer https://www.ebay.com.au/itm/332363552335
Click to expand...

Okay, this circuit has been working well- I've not had any auto start failures since fitting it. I have had the cap go flat and lost the date/ time from the Mobius sitting for a while though. The main point - the Mobius is starting reliably and I'm getting all the driving captured (even if it means digging through incorrect dates/ times to find the relevant files.)

Observing the lights on the Mobius, the rear red LED would pulse when starting the engine previously (even when it didn't fail and continued recording.) Since fitting the timer the red LED continues flashing in a steady sequence with engine starts.

I need to remember and try Radius8's suggestion of stopping the Mobius prior to power turn off. @Radius8 re the components on that timer, I recall the capacitors were rated to 105 Celcius rather than the lower 85 degree spec. The generic NE555 seems to be rated at 70C. Given a timer is normally installed under the dash it doesn't have to contend with the direct radiant heat from the sun, so there shouldn't be any problems. (Mil spec components would be nice but that's not going to happen on a generic timer!)
 
Here you go, the 555 version for military use 😉:

Military grade 555 timer

Rated temperature: -55 to 125 C. They also make an radiation hardened one for space applications. Be prepared to pay like 20x that what the regular 555 cost though.
 
Update. I installed capacitors in my two Mobius cams 4 years 2 months & 3 years 11 months ago, respectively. Both cams start recording when the engine is started. Both hold date & time correctly, & save the last file after the engine is switched off.
 
Both of mine now auto start fine (after the previously mentioned timer mod.) Leave the vehicle sitting for more than 5 days (roughly) and the date time resets.
 
Update. I installed capacitors in my two Mobius cams 4 years 3 months & 4 years ago, respectively. Both cams start recording when the engine is started. Both hold date & time correctly, & save the last file after the engine is switched off.
 
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