The Mobius & Heat Issues

[murcod]

But don't other dash cams use Li-ion batteries too?

 

[jokiin]

But don't other dash cams use Li-ion batteries too?

99% of them

 

[sludgeguts]

Had a daft idea.
Using an extension lens, what if the mobius was mounted to the roof itself?
Pull back / cut a flap in the roof lining, sand back a bit of paint on the underside of the roof to expose bare metal & mount the mobius directly to the bare metal ensuring the mobius' heatsink is making good contact with the roof.

 

[murcod]

Had a daft idea.
Using an extension lens, what if the mobius was mounted to the roof itself?
Pull back / cut a flap in the roof lining, sand back a bit of paint on the underside of the roof to expose bare metal & mount the mobius directly to the bare metal ensuring the mobius' heatsink is making good contact with the roof.

Getting the electronics/ battery out of the windscreen would be a good idea IMHO, but not using the roof panel as a heat sink. Have you ever touched a car's roof (especially a dark coloured vehicle) when it's got the sun on it? You'll burn your hand in Summer! You'd want the electronics inside the cabin- not even between the roof lining and metal roof.

 

[Mrnewbie]

Maybe build a dual LM7805 regulator circuit? An LM7805 regulator IC would provide the required power for either the fan or the camera, but not both. At 1A available current, it falls short by the 230Ma the fan requires to run including 1amp specified for the camera. Mobius data specifies "1A when charging".

I have seen this qoute time and time again...Mobius data specifies "1A when charging".
Why?

On the very first page of the RC tread a fella by the name of Haku took these measurements..

No battery connected• Standby mode: 225mA @ 4.97v
• Standby mode with AV-Out enabled: 265mA @ 4.97v
• Recording 1080p: 305mA @ 4.97v
• Recording 1080p with AV-OUT enabled: 330mA @ 4.96v
Battery connected
• Battery being charged from flat, powered off: 186mA @ 4.97v
• Battery being charged from flat, recording 1080p: average 505mA @ 4.95v

So, with Vid out on we can assume another 40ma or so..from the above measurements
So the max possible current draw with it all ON would around 550ma

even if you add a 260ma fan..your still at 800 or so ma...under the 1A limit of both the USB charger cig plug..and a 7805 1a version..there is a 1.5A version as well.

Which is why I pointed to that fan in post 82# It runs on 160MA..and is smaller as well

Is there some technical reason that I do not understand?

 

[murcod]

You're better off with a over rated power supply- to allow for the sometimes extreme temperatures in a vehicle. (The 7805 could be fitted with a larger heat sink to compensate.) Small fans can be annoying (noise wise) and invariably become noisier with age, so passive cooling is always the more desirable option IMHO... and more reliable.

 

[Isoprop]

I have seen this qoute time and time again...Mobius data specifies "1A when charging".
Why?

On the very first page of the RC tread a fella by the name of Haku took these measurements..

No battery connected• Standby mode: 225mA @ 4.97v
• Standby mode with AV-Out enabled: 265mA @ 4.97v
• Recording 1080p: 305mA @ 4.97v
• Recording 1080p with AV-OUT enabled: 330mA @ 4.96v
Battery connected
• Battery being charged from flat, powered off: 186mA @ 4.97v
• Battery being charged from flat, recording 1080p: average 505mA @ 4.95v

So, with Vid out on we can assume another 40ma or so..from the above measurements
So the max possible current draw with it all ON would around 550ma

even if you add a 260ma fan..your still at 800 or so ma...under the 1A limit of both the USB charger cig plug..and a 7805 1a version..there is a 1.5A version as well.

Which is why I pointed to that fan in post 82# It runs on 160MA..and is smaller as well

Is there some technical reason that I do not understand?

The 1A is recommended by the developer. When recording and charging at the same time the Mobius may draw over 600mA. The figures measured by myself and others are average values. Peak values can be higher.
The 1A specified should be considered as the min. safe value to use. What has to be avoided at all costs is a voltage drop during peak current draw, for example when writing data to the card. This would result in the charger supplying less voltage which would in turn force the charging IC to stop charging the battery for a split second. During this short time the camera would draw voltage from the internal battery and after a few milliseconds, when the write cycle is completed, the charger would again supply the necessary voltage and the charging IC would start charging the battery again. These fast charging/discharging cycles will overheat the battery, overheat the charger IC and lead to premature failure of the battery and possibly the Mobius as well. One battery only lasted one week when the camera was used with an under-rated charger. You will most likely get away with a high quality charger with a slightly lower spec., but why take the risk?

 

[jokiin]

You will most likely get away with a high quality charger with a slightly lower spec., but why take the risk?

I agree, you have a manufacturer that goes to the trouble to actually advise what's required then why not follow their advice instead of thinking it's some sort of challenge to be tested

 

[Necromancer]

IMO an active cooling is too big, too complicated, distracting and overall not required. Throwing a heatsink on top of it is enough.

 

[Mrnewbie]

....get away with a high quality charger with a slightly lower spec., but why take the risk?

But why take the risk?

Because, I'm just not right in the head. There is something just plain wrong with me
I tend to take one gadget..combine it with a 2nd gadget..and make something to fill a specific use.
This is one of those things. Here is the plan..

Mobius 24/7 Dashcam and Mobile Security Camera mounted in truck.
Mobius + Fan + RX mitter.

I agree normal dash camers don't need a fan a heat sink upgrade should be fine.
I accept that I will..the RX unit gets hot too!

Everything is all built and working.....on the bench, no internal batttery

So my last question to ISO is would I be better off powering the camera through the stock battery plug..or through the mini usb?
Does powering throught the mini usb..engage the charging circuitry..even with no battery present?

 

[Isoprop]

But why take the risk?

Because, I'm just not right in the head. There is something just plain wrong with me
I tend to take one gadget..combine it with a 2nd gadget..and make something to fill a specific use.
This is one of those things. Here is the plan..

Mobius 24/7 Dashcam and Mobile Security Camera mounted in truck.
Mobius + Fan + RX mitter.

I agree normal dash camers don't need a fan a heat sink upgrade should be fine.
I accept that I will..the RX unit gets hot too!

Everything is all built and working.....on the bench, no internal batttery

So my last question to ISO is would I be better off powering the camera through the stock battery plug..or through the mini usb?
Does powering throught the mini usb..engage the charging circuitry..even with no battery present?

It's much better to power the Mobius with external USB power. The camera was specifically designed to be powered with external USB power with or without the battery installed!
If you tap into the battery plug you'll run into other problems, namely charging, but much more important any voltage above 4.2V will burn the circuitry. The battery connector was designed for connecting to a LiPo cell, it was not designed to be misused by applying external 4V power.
In your case, the best solution would be to use a supercap pair in place of the battery. This will keep the RTC (Real Time Clock) running when power is removed. Unfortunately, the caps aren't officially available yet.

 

[fatpanda]

What is the hold up with the supercap Isoprop?

 

[Isoprop]

What is the hold up with the supercap Isoprop?

Maybe he has more important things to do. Sorry, but I really don't know.

 

[Passion 4 Pro]

Anywhere we can get data sheet of this kind of battery ? For safety learning.

 

[Seboni121]

I've been using mine in the car all day 6 hours at least and yes it gets warm but not overly, just got warm not hot !

 

[Passion 4 Pro]

I've been using mine in the car all day 6 hours at least and yes it gets warm but not overly, just got warm not hot !

Let the number talk will be more exactly. Different people might have different feeling about the warm/hot.

 

[Seboni121]

Well it's happened ! the camera went into full melt down and no longer works! So a refund will now be asked for !

 

[murcod]

Well it's happened ! the camera went into full melt down and no longer works! So a refund will now be asked for !

Do you know it's an over heating issue for certain? Does the case - or some other part - show signs of excess heat?

 

[Seboni121]

No no outward signs but it went really very hot ! I've tried to get it to come on but to no avail, not melted as I can remove the sd card with no issues but the lens on the camera looks damaged a white spot inside the lens , I did think of opening it up but thought better of it (warranty) so I will be getting a replacement as it was fine up to that point

 

[russ331]

Just wondering if it's possible for a USB car charger to malfunction, delivering 12v to the camera instead of the usual 5v, thereby frying the circuitry?

PS sorry to hear about your loss.