Battery temperature..capacator option

[grnbrg]

LiPo batteries most certainly can catastrophically fail. I do a lot of RC stuff, and it does happen. The battery here is probably a 3 cell (in series) ~2000 mAH, 30-40C damaged LiPo.

With that said, I really can't see the little 1S 400mAH cells in cameras doing significant damage. But I wouldn't say it's impossible.



grnbrg.

 

[jokiin]

They don't normally do a lot of damage but can damage the camera though

 

[Sue]

Just make sure your camera is shielded from direct overhead sun. ...

This puzzles me. when I bought the Mivue Dashcam, the instructions said not to have it in the sun. However, given that the windscreen is in the sun when one is driving, how is it possible to keep it shielded? In my car... it just is not. So, are we supposed to drive only at night? Truly, the manufacturers must be laughing all the way to the bank (the Mivue failed just outside the warranty period)

 

[Sabe]

There is important lesson hidden in that video: don't ever let you hamburger alone, somebody might eat it

 

[Nigel]

This puzzles me. when I bought the Mivue Dashcam, the instructions said not to have it in the sun. However, given that the windscreen is in the sun when one is driving, how is it possible to keep it shielded? In my car... it just is not. So, are we supposed to drive only at night? Truly, the manufacturers must be laughing all the way to the bank (the Mivue failed just outside the warranty period)

You don't have to keep your windscreen shielded, just position the camera under the sun strip at the top of the windscreen, or if your car doesn't have any tint or black dotted area to put the camera under then add your own, either a full aftermarket sun strip or just a bit of black sticky tape above the camera. You don't have to prevent all sun reaching the camera, just the mid day vertically overhead sun in the middle of summer that is capable of heating the camera up to 70 degrees C.

 

[Nigel]

...The battery here is probably a 3 cell (in series) ~2000 mAH, 30-40C damaged LiPo.

With that said, I really can't see the little 1S 400mAH cells in cameras doing significant damage. But I wouldn't say it's impossible.

Now I'm worried, I just replaced the lipo battery in my mini 0803 by a 25C battery... it is only a 1 cell battery so it wont give the 800 watts of power that your 3 cell would, but it is still capable of 35 watts which may be enough to start a small fire. However it is not a damaged one - always be very careful of damaged lipo batteries, and don't stamp on burning ones with your feet - burning lithium and feet don't go well together!

My mini 0803 now records for 35 minutes on internal battery

 

[country_hick]

always be very careful of damaged lipo batteries, and don't stamp on burning ones with your feet - burning lithium and feet don't go well together!

Is there a story that goes along with this?

 

[jokiin]

Is there a story that goes along with this?

The video posted above at a guess

 

[Nigel]

Is there a story that goes along with this?

As can be seen in the video above, you wont put a lithium fire out by stamping your feet on it, you want a powder fire extinguisher, or just wait until it burns itself out which wont take long for any normal sized lithium battery.

You are likely to get bits of burning lithium stuck to your melting shoes which could be at well over 1000 degrees C.

If the lithium gets through to your feet which are made mainly of water then this is a video of someone putting a dismantled lithium battery in water:

 

[grnbrg]

As can be seen in the video above, you wont put a lithium fire out by stamping your feet on it, you want a powder fire extinguisher, or just wait until it burns itself out which wont take long for any normal sized lithium battery.

You are likely to get bits of burning lithium stuck to your melting shoes which could be at well over 1000 degrees C.

If the lithium gets through to your feet which are made mainly of water then this is a video of someone putting a dismantled lithium battery in water:

Ok, I've seen this a couple of times in this thread. (And sorry to hijack...)

Nope. LiPo batteries don't work like this. There is no metallic lithium in them at all. It's a salt, and in solution.

In a lipo fire, you have burning plastic and electrolyte and possibly some oxygen at the start from internal deterioration. Still not something you really want to stomp on.

An interesting (if technical) discussion of lipo chemistry and why batteries fail is here: http://barnson.org/node/1842



grnbrg.

 

[Nigel]

Ok, I've seen this a couple of times in this thread. (And sorry to hijack...)

Nope. LiPo batteries don't work like this. There is no metallic lithium in them at all. It's a salt, and in solution.

In a lipo fire, you have burning plastic and electrolyte and possibly some oxygen at the start from internal deterioration. Still not something you really want to stomp on.

An interesting (if technical) discussion of lipo chemistry and why batteries fail is here: http://barnson.org/node/1842



grnbrg.

Thanks for that link

Normally when you see video of a lipo burning, it does burn like lithium rather than like plastic, at least for a short while before dying down and turning into a plastic fire. I assume this is because there is metallic lithium in the battery. As stated in your link: "If a Lithium battery is overcharged or charged too quickly, you end up with LOTS of excess free lithium on the anode (metallic lithium plating)...".

I'm no expert though...

 

[bn880]

Carrying a phone, tablet, and laptop on an airplane is safe, because airplanes do not get hot enough to be a problem. Passengers do not tolerate 45 C: they tend to riot or lose consciousness -- both of which are serious emergencies airlines could do without.

There are a few things things you can't do safely do to a lithium battery:

• Over-charge
• Over-discharge
• Puncture the battery
• Short-circuit the battery
• Expose it high temperatures (ie. above 45 C)

This is not the whole truth. Because portable computing devices today (mobiles/tablets) are exposed to the same temps often as dashcams and do not have LiIon or LiPo fires. They are left all the time in the car when it gets up to 60 or 70C and no fires generally. lots of lithium batteries will work past 45C, the hobby shop ones included (example Turnigy 1C nano tech up to 60C with 5% swell).

 

[Pariah Zero]

There is a difference between a battery being damaged by heat, which can result in significant shortening in capacity and lifespan, and a battery bursting into flame.

Both are bad in their own way.

 

[Street Guardian USA]

Battery based dashcam products are a bad investment when used long term in a car. Stick with supercapacitor based systems. The numbers below will be worse in Texas etc.

 

[bn880]

There is a difference between a battery being damaged by heat, which can result in significant shortening in capacity and lifespan, and a battery bursting into flame.

Both are bad in their own way.

Yes and? Neither is a big problem if you try a good quality LiPo.

 

[bn880]

Battery based dashcam products are a bad investment when used long term in a car. Stick with supercapacitor based systems. The numbers below will be worse in Texas etc.

Never had any issues with Turnigy NanoTech LiPos in extreme heat for over a year, capacity is great AND I can record with the car battery being dead or camera out of car.

Capacitor may be a good investment for some people, especially for 100% permanent installs where more years of reliability are more important than recording without car power.

 

[Nigel]

Yes and? Neither is a big problem if you try a good quality LiPo.

I guess all the hundreds of recent battery failure threads are all due poor quality LiPos?

... searches for recent battery failure threads ...

Odd ... I can't find any!

 

[Pariah Zero]

You don't get to select the battery a dashcam manufacturer uses; you're going to get the cheapest the Chinese manufacturer could get.

You don't see many threads about battery failures because very few dashcam a use them.

When they fail, people tend to contact the seller for replacement, instead of complaining on forums.

Given pier21 sells (and replaces) dashcams, he's in a far better position to judge reliability with hard numbers instead of anecdotes.

 

[Dashmellow]

I guess all the hundreds of recent battery failure threads are all due poor quality LiPos?

... searches for recent battery failure threads ...

Odd ... I can't find any!

There have been numerous reports of dead cameras and operational glitches on DCT that have ultimately been shown to be caused by failed or dying batteries but they simply don't get posted as "battery failure threads".

 

[bn880]

Yes, I am not saying that as a consumer you can bet on having good lipos in a dashcam you buy. Don't get me wrong. I am just saying that if you are handy and can be bothered, you can put in a top notch lipo into a good dashcam, and have a massive win. (sort of speak). If you don't want to dig inside, then yes you can at least bet on capacitors being more reliable (FOR NOW). Wait until caps are so desired that cheap cam manufacturers put them in, only to buy the cheapest stocks from the cheapest factories., Then you're going to have swollen/dying/popping caps too (and without ability to record with the cam unpowered anyway)

There have been lots of cams with dead LiPos, pretty much all due to crap LiPos.

For the most lipos are no good, at least if you have the camera in the car all the time like i have.
The operating temperature envelope for lipos get busted many days thru the year even as far north as Denmark is, and in winter it can allso drop to a problematic low temperature, though with out geological placement its rare for those really nasty cold days.
I think this winter we dident even get minus 2 digit temperatures, and if we did it was 3-4-5 days at most.
Last summer was good here with about 2 weeks of +30 deg C temperatures, and another 2-3-4 weeks with +25 deg C temperatures.
And those outside tempeartures is enuff for a car to reach lipo killing temperatures inside the car.

Allso if you wish to use features as parking guard where the camera is allways powered, capasitors is a must as lipos are not meant for constant charging, and not least a running warm camera in a even warmer sun baked car will cook the lipos.

My dataplan is 6 Gb a month, but i would never use that to upload anything, if i have captured anything intresting it will just have to wait to i get home to my cable connection before it go to the share sites.
On a normal month i think i use 1 Gb, but so small dataplans is not to be found here, anyway i hate that phone and cant wait untill i can trow it avay and be phoneless again.

I guess all the hundreds of recent battery failure threads are all due poor quality LiPos?

... searches for recent battery failure threads ...

Odd ... I can't find any!

You don't get to select the battery a dashcam manufacturer uses; you're going to get the cheapest the Chinese manufacturer could get.

You don't see many threads about battery failures because very few dashcam a use them.

When they fail, people tend to contact the seller for replacement, instead of complaining on forums.

Given pier21 sells (and replaces) dashcams, he's in a far better position to judge reliability with hard numbers instead of anecdotes.

There have been numerous reports of dead cameras and operational glitches on DCT that have ultimately been shown to be caused by failed or dying batteries but they simply don't get posted as "battery failure threads".