Battery Safety.

[smitty69]

Hi All,

Lets talk about Li-ion Batteries, and Li-Polymer Batteries.

I'm looking at getting a new cam - and I have noticed some come with a "super capacitor" instead of a battery.

Lets take the Mini 0803 as that would be good for me as progression from my 0801's. In the context of Motion detection.....................

There is a thread here
http://dashcamtalk.com/forum/threads/what-about-motion-detection.6134/

In it Jokiin says a)
"if you want to use parking mode the camera should not use an internal battery"

He also says b)
"also requires being powered constantly to work which is not good given the internal battery"

He also says c)
"powering it all the time isn't advisable though as it has a built in battery"

He also says d)
"will constantly be getting charged and topped up, in warm weather that's a big problem, best case scenario is short battery life, worst case it swells up and ends up catching fire"

He also says e)
"Not Li-ion, worse, Li-po"

Now - please correct me if I am wrong here - as I am not technical when it comes to electricals.

The camera is powered via a cigarette socket when driving - it is actually designed SPECIFICALLY to run off such a socket - and will not record for long on the internal battery alone as it will quickly go flat.
In points b) c) d) e) above - he is saying DONT use power all the time as it is basically dangerous.

Infact - its worse with these because they have a Li-Po battery.

So I am confused - why design a car camera which uses an internal Li-Po battery, is CONSTANTLY getting charged up (well it is in the 0801 anyway) on and off with general driving use.
So is there a difference between the way the battery is charged up under different usage conditions?
a) Motion Detect - Jokiin says - quite clearly - "DONT USE IT WITH POWER FROM THE CAR".
b) Normal Drive Recording - its ok to use it with power from the car.

Whats the score here - it would seem to me that BOTH modes of use are the same in terms of what happens with the battery in the camera - so why are they BOTH NOT dangerous, and ONLY motion detect is dangerous?

See what I mean?
Thanks



2.

 

[jokiin]

The thing that makes the problem worse when powered all the time is firstly that it just never gets a break, second but far worse is that the temperature in a locked car parked in the sun can easily exceed 30c above ambient temps, pretty sure you wouldn't ever drive a car when it's 70c plus inside so the temp when driving is not so extreme, when parked and powered though you can easily exceed these temps, LiPo batteries are pretty stable up to around 40c, not so once the temps start getting higher though

 

[smitty69]

Hi Jokiin - that doesnt answer the question at all.

All cameras are powered all the time - they dont work if they arent.

If I get to my car, it can EASILY be 70 degrees inside and higher - I turn on the car, the battery in the cam is already at 70 degrees plus and now it starts charging.

THIS MUST HAPPEN ALL OVER THE WORLD CONSTANTLY.

I dont get it.

 

[jokiin]

Batteries are cheaper and easier to do than capacitors, does this help you understand the logic in why so many use them?

Some better quality products will have some protection circuitry to cut power to the battery when they're over temp, these are in the minority though

 

[smitty69]

"LiPo batteries are pretty stable up to around 40c not so once the temps start getting higher though"

40c is nothing at all - 104f - this can happen anywhere in the world at any time. A parked car can easily reach 40 inside, so when you get in - you have an immediate problem here if the battery starts to accept charge.

 

[jokiin]

Correct

 

[smitty69]

I understand the economics Jokiin - but this is disgraceful.

 

[smitty69]

If my understanding here is correct - people using LI-Polymer batteries in car cameras WILL DIE.

 

[jokiin]

I don't think people are going to die, some electronics might die though

 

[smitty69]

But you said
"will constantly be getting charged and topped up, in warm weather that's a big problem, best case scenario is short battery life, worst case it swells up and ends up catching fire"

What happens if a car camera battery bursts into flames with the car going down a motorway in the outside lane at 70mph?

Also - best and worse case etc - how does all this fare once the camera and its internal battery have been used daily for 12 months?

 

[Tobi@s]

Well I guess it doesn't burst in flames from one second to another. There will be smoke etc before it starts to burn. Enough time to jump out of the car (Or enoough time to throw the camera out? )
The problem is: What happens when you are NOT in the car?

 

[smitty69]

That test doesnt show what happens when they are charged in high temps over 40c - this is the main concern. Do you know of such a video?

 

[Tobi@s]

No I have never seen such a video. I think in most cases nothing happens. But I don't want to try that in my car.

 

[smitty69]

What would happen at 70mph to a 75 year old driver if this happened?

 

[Tobi@s]

He'd get grilled I guess

 

[jokiin]

Roast retiree, life's full of what ifs

The odds of it catching on fire while you're driving are about the same as your GPS catching fire, you wouldn't leave your GPS powered and running in a locked car parked in the sun and expect it to survive too long either, not something people are likely to do though

 

[niko]

@smitty69, - to avoid arguing, I have 4 answers to your concern:

1. Easiest is to take advice of all above members ( veterans ). They don't write advice out of nothing. There is a long time experience behind any advice.
2. If you still dont trust advices, - you may read through whole forum and collect information step by step, piece by piece.
3. you can buy lets say 10 different LiPo batteries which are used in dashcams ( bulk price is about 60-70 usd for 10pcs shipped ) and test only batteries: put them on dash of your car and drive around few month along with car parked under the sun on daily bases under direct sun. Then you may see what happens.
4. Write to all Korean and Taiwanese high-end dashcam manufacturers and ask them: why majority of their 200-500 usd dashcams are based only on supercaps ( capacitors ).

 

[wrdjr20]

If a lipo catches on fire in a car, the car burns up. Lipo's can burn at temperatures in excess of 1100C. There is a video of a guy's SUV burning up after he decided to charge his RC battery inside the vehicle in the hot sun. Lipo's start to delaminate when the temperature rises above 90C and this can lead to self ignition. Since the internal temperature of a Lipo increases when charging or discharging it, prolonged ambient opperating temperatures up to 40C are safe, approaching 60c greatly reduced battery life, above 60C dangerous.
The fact is, we all live with lipo batteries. They are in cell phones, GPS devices, mp3 players, tablets, laptop computers, cameras, dashcams, RC aircraft, and the list goes on. They are safe and robust when used and maintained properly. If it swells or stops holding a charge, replace it. If its in a hot parked car, remove it, or al least park in the shade and crack the windows. If it has not been charged recently, charge it. If it has been plugged in for long period of time unused, unplug it.

 

[kamkar]

Lipo batteries can be quite nasty, and for sure when one of then let Loose the smoke of death it dont smell good.

I do think its common practise in RC to not leave lipos unattended while charging, and i for one store mine in the oven in my kitchen as i dont use it for cooking.

But in RC we are normally talking about large ( +3000 mah ) batteries and more than 2 cells, personal i drive with 3 cell batteries and not smaller than 5000 mah.
Offcourse there is small RC Things that allso use small batteries, i myself allso have a 1 : 24 car witch i run on 2 cell < 360 mah batteries, but in general its large batteries, as my friends boat witch run on 2 x 6 cell 5400 mah batteries.

But i doubt the small batteries in dashcams is a ticking bomb, i guess most cameras is made of plastic with fire inhibitors in it so a dying battery should be some what contained within the plastic housing.

I am aware of several smartphones - tablets - mp4 playes and so on more or less blowing up, but please take into consideration these are densely packed devises, so pressure have a chance to build up before it reach the point where it break.

The Dashcams i have seen taken apart seem to have "plenty" of room inside, i think the battery in my innovv c1 and mobius could swell up without me noticing it.

The guy torching his car proberly had the battery lying on the car seat, and that is just asking for truble, i have my batteries in a stainless pot when i charge mine at home.

PS. i have to admit the first weeks i used my mobius in the rear window it was with the battery, that is now swapped out for a couple of capasitors.

PPS. Me and my friend have been dealing with lipos in a RC for 4-5 years now, and so far we have only had 1 battery fail ( while charging )
We have had no in car faliures though we drive our Little RC cars thru Water and in Winters so Cold the transmission freeze up if car is left wet and unattended for 10 minutes, and in hot summer wheather with what the sun and the car itself can provide of heat.

I dont fear lipos, but i will not have them in anything witch is in my car all the time, and my dashcams is a permanent install.

 

[Boxerman]

What would happen at 70mph to a 75 year old driver if this happened?

Well the 75 year old is hardly likey to be putting 10amps into his dashcam is he?


Frank