Oldest Mobius

[country_hick]

I can agree with your RC use assessment. However, a super capacitor has been made just for dash cam use. A NIMH battery should also be available for dash cam use if it is a reasonable design element.

 

[Dashmellow]

Why do dash cams not use a nicad or nimh battery? The battery does not need to hold a charge for an exceptionally long time in this application.

I can agree with your RC use assessment. However, a super capacitor has been made just for dash cam use. A NIMH battery should also be available for dash cam use if it is a reasonable design element.

Nickel–cadmium batteries are toxic to the environment and suffer from "memory effect", where the battery "remembers" the point in its charge cycle where recharging began and during subsequent use suffers a sudden drop in voltage at that point, as if the battery had been discharged. This gets worse over time. NiCads are more or less obsolete at this point and would be a poor choice for a Mobius.

NiCads, along with NiMH (nickel–metal hydride) would not be suitable for a camera such as the Mobius for other reasons as well. Neither possess the required energy density or size/weight ratio of a Lithium-Polymer battery nor are they available in a form factor that would fit inside a small camera like the Mobius.

Actually, the battery does in fact need to hold a charge for a reasonably long time in order to maintain the date and time settings.

 

[Dashmellow]

One thing about the Mobius battery that bothers me... It's a LiPo Battery and LiPo batteries should be stored at 40%-->60% charge. However, in a dash cam set-up, it's going to be stored with almost 100% charge; which is the worst possible storage condition. A LiPo stored at near 100% charge deteriorates over time. While I've been lucky with my Mobius so far, the more I dig into LiPo battery information, the more I realize it's time to switch to a capacitor.

The 40-60% charge is recommended for long term storage of lithium batteries. In day to day usage, lithiums generally benefit from being topped off periodically. I guess if one is concerned with leaving the Mobius battery fully charged it should be a simple matter to manually drain it down partially.

With a small, modestly priced, easily replaced battery like the one that comes with a Mobius, one should probably expect at least a year or more (maybe two?) of service from the cell with reasonable care. Having said that, I agree about using super-capacitors in a Mobius dash cam and wouldn't have it any other way. On the other hand I have a Mobius I've been carrying around as a pocket cam for almost a year now and always keep it fully charged. It still has the original battery and it's doing fine.

 

[BobDiaz]

Nickel–cadmium batteries are toxic to the environment and suffer from "memory effect", where the battery "remembers" the point in its charge cycle where recharging began and during subsequent use suffers a sudden drop in voltage at that point, as if the battery had been discharged. This gets worse over time. NiCads are more or less obsolete at this point and would be a poor choice for a Mobius.

NiCads, along with NiMH (nickel–metal hydride) would not be suitable for a camera such as the Mobius for other reasons as well. Neither possess the required energy density or size/weight ratio of a Lithium-Polymer battery nor are they available in a form factor that would fit inside a small camera like the Mobius.

Actually, the battery does in fact need to hold a charge for a reasonably long time in order to maintain the date and time settings.

NiMH (nickel–metal hydride) batteries would work for the Mobius as a dash camera because we really don't need a high power density. Most of the power is during shut down and the stand-by current is next to nothing. You are correct about the form factor. LiPo can be built in a flat shape of whatever size, BUT NiMH (nickel–metal hydride) isn't so easy to get into that shape.

 

[Dashmellow]

NiMH (nickel–metal hydride) batteries would work for the Mobius as a dash camera because we really don't need a high power density. Most of the power is during shut down and the stand-by current is next to nothing. You are correct about the form factor. LiPo can be built in a flat shape of whatever size, BUT NiMH (nickel–metal hydride) isn't so easy to get into that shape.

I guess I was thinking in terms of the usual 1 to two hour run time for the standard Mobius batteries rather than for dash cam use. Still, a NiMh, assuming it was tiny enough to fit might not have what it takes. Don't really know.

 

[country_hick]

I was thinking of a 3 to 10 minute run time for a dashcam. I would think a NIMH battery could last that long even in a small package. As far as it being able to be packaged in the correct shape I would think that flat or round the chemical reactions in a battery would be the same.

 

[Dashmellow]

The notion of putting a battery that doesn't exist into a Mobius doesn't seem worth discussing any further.

 

[country_hick]

Small and thin rechargeable button type batteries wired in series could work as a power source. The only part requiring manufacturing would be a container to hold them.

This may be the perfect solution for a NIMH battery.
http://www.varta-microbattery.com/e...-button-cells/all/technology-description.html
Not knowing dimensions this could be to big or maybe fit perfectly.

There are other NIMH button batteries I found in a quick search.
https://www.amazon.com/gp/B00JPPLIKW
http://www.microbattery.com/products/rechargeable-nimh-button-batteries

I could be wrong but I suspect the rechargeable 9 volt batteries already contain NIMH batteries internally that would fit the mobius need. Open a 9 volt battery up and you could find several miniature aaaaaa or something batteries inside. They might not fit the mobius because of length but the width I doubt would be a problem. Some 9 volt batteries have thin square batteries instead. I tore apart a some worn out 9 volt batteries before. If these very small batteries would not fit the mobius they could be adapted for the larger dash cams.

 

[BobDiaz]

I guess I was thinking in terms of the usual 1 to two hour run time for the standard Mobius batteries rather than for dash cam use. Still, a NiMh, assuming it was tiny enough to fit might not have what it takes. Don't really know.

I won't beat this horse any more, but if we compare the capacity of a NiMh battery to that of a super capacitor, the battery wins hands down. You are correct, this is only a hypothetical issue seeing as the battery doesn't exist and besides, for dash cam use, the super capacitor is a lot better than any battery.

By the way, per kg or per pound, the NiMh is about 1/3 the capacity of the LiPo batteries. I don't know how that works out on volume.

 

[Dashmellow]

I've been thinking about the OP of this thread........"Just wondered who has had their Mobius the longest on here and if it's still going strong?", so I thought I'd share my experience.

This has been one of the harshest, coldest winters in memory here in rural New England and my truck lives out in the driveway with no garage. The result is that as of yesterday I couldn't exactly remember when I last checked the footage of my rear facing Mobius because climbing around in the back of my vehicle to retrieve the microSD card is about the last thing I feel like doing in this weather. (Here it is the 4th of March and we are still getting temperatures in the single digits and it snowed yet again last night!, Ughh!)

There have been quite a few times over the last month or so when the temperature has been well below zero (Fahrenheit) and my Mobius cam flashes red three times on start-up but then won't begin recording. It takes about 60-90 seconds for the DSP to come up to temperature so that the camera can begin to operate and it then needs to be rebooted with a quick unplugging and replugging when that happens. According to @Isoprop, the DSP is rated down to 14 degrees F and that is indeed about the temperature below which the start-up problem manifests.

So yesterday, I decided that I really ought to have a look at the footage and see how everything is working (or not). After transferring all the clips (5 minutes each) to my computer and reviewing them I found that the camera is functioning absolutely perfectly and hasn't skipped a beat. It just keeps recording and overwriting the older footage as it should. The only issue is that when the ambient temperature fell to the extreme of -12 degrees Fahrenheit below zero (-24.4 Celsius) the lens went slightly out of focus until it warmed up and then returned to normal.

I've talked about these cold weather Mobius issues elsewhere here at DCT but didn't really get into the reliability of the footage too much. I thought I'd post about it here because this camera is a first generation Mobius (with a "B" lens module and super-capacitors installed) and despite the difficulties in extreme cold weather it is a true workhorse, doing what it is supposed to do, day in and day out for well over a year now.

 

[horaceCJ]

The only issue is that when the ambient temperature fell to the extreme of -12 degrees Fahrenheit below zero (-24.4 Celsius) the lens went slightly out of focus until it warmed up and then returned to normal.

I noticed this also in really cold weather but I thought it's condensation and it disappears (in 3-4 minutes) as the lens and camera get warmer. I never tried to clean the lens in the first minutes in order to check this theory...

 

[Dashmellow]

I noticed this also in really cold weather but I thought it's condensation and it disappears (in 3-4 minutes) as the lens and camera get warmer. I never tried to clean the lens in the first minutes in order to check this theory...

In my case, I'm sure it wasn't condensation, it was contraction from the extreme cold. In fact, at -12 degrees Fahrenheit there would be very little moisture in the air to condense on the lens within the first moments after starting my vehicle. Also, I've seen what condensation looks like on dash cam lenses and there is usually a kind of soft "halo" around brighter objects, whereas what happened for me when it was so cold was a definite soft focus shift that slowly returned to normal sharpness.

 

[horaceCJ]

I'll have to wait the next winter to check this, spring is slowly coming, although we had some snow storms yesterday. Too pity that I didn't kept a sample.

 

[Dashmellow]

I'll have to wait the next winter to check this, spring is slowly coming, although we had some snow storms yesterday. Too pity that I didn't kept a sample.

I also wish I had a video sample to show you but there is only so much room on my hard drives to keep old footage. Basically, it looked "soft" at extreme sub zero temps and then became sharp after warm-up.

Spring still seems a long way off here. We still have several feet of snow on the ground, tonight it will go down to 17°F (-8.3°C) and tomorrow night it is predicted to go down to -2°F (-18.8°C). Maybe it will be cold enough to capture the focus shift on the M0bius lens but that only happened around -12°F - 15°F as far as I know?