Electronics adventure, faulty e-cigarette autopsy.
Jun 25, 2017 20:14:12 GMT 1
viscount, groth, and 1 more like this
Post by radiostationx on Jun 25, 2017 20:14:12 GMT 1
Autopsy : electronic cigarette teardown
Hi guys,
I thought you may like another of my electronics adventures, I received quite a few "NWAN likes " on previous teardowns.. so here goes.
A friend of mine had this electonic cigarette which went faulty ,very faulty.
He puffed away in his car in works car park, went back in to work, returned for another puff a few hours later and found his device would no longer work.
More on that later but he asked me to have a look this afternoon over a beer or two and see what I could salvage, if anything.
After first look, I "suggested" (expletive deleted) we go outside in the garden before doing anything.
Im glad we did.
In short,I knew what I was dealing with and indoors wasnt an option.
The device itself, Its quite a posh thing with temperature control, wattage control and all kinds of menu thingys to play with all powered by a single 18650 rechargeable battery.
Here is his working spare one that he puffed away on this aft .
OLED dot matrix display which is easy to see in daylight.
Anyway lets get in there and have a look.
Here are the parts stripped out which took longer than expected due to the fashionable new eco solder which has minimal lead and takes loads of heat to get off. Plus a very evident issue which I will tell you about towards the end.
The pcb is very well made, double sided . All the solder pads for the devices seem very neat and tidy. All soldered by machine apart from a few joints for the cables. The tank screws into the top thread on the far left. There are 3 tactile buttons and a micro usb socket for charging the battery cell.
Amazing what they can fit in nowerdays.
The other side with the microcontroller U1 which controls time and wattage etc by electronic pulses. Also a feature on the board is over current protection.
To the right of U1 , That resistor/capacitor bank to the right hand side has some insanely small chip devices in it.
I doubt I would be able to get those freehand with an iron !
Next the real issue, lets have a closer look at the battery holder..
Hmmmm interesting !
The other side, Even more interesting !
The battery ...oh dear !
The battery had arc welded itself into the holder.
This is why I said that stripping down took longer than expected. A very sorry mess indeed.
Fortunately, my friend only used reputable batteries.
This one is an LG electronics 30 amp, 2500mah 18650 high current drain LI-ION battery. These are not cheap.
What I think happened is that eliquid has leaked from the tank & worked into the battery sleeve over time and caused a direct short inside the holder. Very close to a fire /explosion here. The battery sleeve has totally broken down/burned away on one side where the direct short path has taken place.The casing of the battery has contained the short but the top cap is in a very bad way and has been distorted by the forces involved.
Over current protection on the pcb could not work initially as the path of the current was directly through the battery casing unmonitored by the pcb and its safeguarding circuits.
The battery could flip its cap and pop at any time.
Lithium ion Rechargeable batteries are extremely dangerous things to dismantle.
Warning : Exposing the innards to free air makes them spontaneously combust.
Sparks and shards of moulten metal fly around in all directions.
Fires can start many hours after dismantling too.
Hence the reason we went outside straight away after I had an initial peek.
As soon as I removed the battery (with great care..gloves and goggles !) I put it deep in a tub of garden sand.
So, dont medal with these or any other rechargeable cells as you will come off worst.
Take a look on youtube at 18650 fires and you will see my way of thinking.
Needless to say My friends car could have been written off by fire if the battery casing had not held up to the punishment it received. A good advert for LG electronics perhaps.My friend did say that when he returned to the car there was a funny smell but didnt pin it down to the eciggy until he found it would not work when he picked it up a few minutes later.
The ecig aluminium casing probably helped absorb the heat build up acting like a giant heat sink and containing the smouldering plastic within.
I would count this as a lucky escape.
There is tremendous energy in a single cell, in a high current 18650, especially so.
Any wonder why airlines have such "heavy" regs on the carriage of bulk li ion batteries.
Hope you found this interesting.
Mike.
PS laptop batteries usually have 6 or 8 of these batteries in series solder tagged and encased in a plastic shell.
USB powerbanks are another application where 18650s are used.
Hi guys,
I thought you may like another of my electronics adventures, I received quite a few "NWAN likes " on previous teardowns.. so here goes.
A friend of mine had this electonic cigarette which went faulty ,very faulty.
He puffed away in his car in works car park, went back in to work, returned for another puff a few hours later and found his device would no longer work.
More on that later but he asked me to have a look this afternoon over a beer or two and see what I could salvage, if anything.
After first look, I "suggested" (expletive deleted) we go outside in the garden before doing anything.
Im glad we did.
In short,I knew what I was dealing with and indoors wasnt an option.
The device itself, Its quite a posh thing with temperature control, wattage control and all kinds of menu thingys to play with all powered by a single 18650 rechargeable battery.
Here is his working spare one that he puffed away on this aft .
OLED dot matrix display which is easy to see in daylight.
Anyway lets get in there and have a look.
Here are the parts stripped out which took longer than expected due to the fashionable new eco solder which has minimal lead and takes loads of heat to get off. Plus a very evident issue which I will tell you about towards the end.
The pcb is very well made, double sided . All the solder pads for the devices seem very neat and tidy. All soldered by machine apart from a few joints for the cables. The tank screws into the top thread on the far left. There are 3 tactile buttons and a micro usb socket for charging the battery cell.
Amazing what they can fit in nowerdays.
The other side with the microcontroller U1 which controls time and wattage etc by electronic pulses. Also a feature on the board is over current protection.
To the right of U1 , That resistor/capacitor bank to the right hand side has some insanely small chip devices in it.
I doubt I would be able to get those freehand with an iron !
Next the real issue, lets have a closer look at the battery holder..
Hmmmm interesting !
The other side, Even more interesting !
The battery ...oh dear !
The battery had arc welded itself into the holder.
This is why I said that stripping down took longer than expected. A very sorry mess indeed.
Fortunately, my friend only used reputable batteries.
This one is an LG electronics 30 amp, 2500mah 18650 high current drain LI-ION battery. These are not cheap.
What I think happened is that eliquid has leaked from the tank & worked into the battery sleeve over time and caused a direct short inside the holder. Very close to a fire /explosion here. The battery sleeve has totally broken down/burned away on one side where the direct short path has taken place.The casing of the battery has contained the short but the top cap is in a very bad way and has been distorted by the forces involved.
Over current protection on the pcb could not work initially as the path of the current was directly through the battery casing unmonitored by the pcb and its safeguarding circuits.
The battery could flip its cap and pop at any time.
Lithium ion Rechargeable batteries are extremely dangerous things to dismantle.
Warning : Exposing the innards to free air makes them spontaneously combust.
Sparks and shards of moulten metal fly around in all directions.
Fires can start many hours after dismantling too.
Hence the reason we went outside straight away after I had an initial peek.
As soon as I removed the battery (with great care..gloves and goggles !) I put it deep in a tub of garden sand.
So, dont medal with these or any other rechargeable cells as you will come off worst.
Take a look on youtube at 18650 fires and you will see my way of thinking.
Needless to say My friends car could have been written off by fire if the battery casing had not held up to the punishment it received. A good advert for LG electronics perhaps.My friend did say that when he returned to the car there was a funny smell but didnt pin it down to the eciggy until he found it would not work when he picked it up a few minutes later.
The ecig aluminium casing probably helped absorb the heat build up acting like a giant heat sink and containing the smouldering plastic within.
I would count this as a lucky escape.
There is tremendous energy in a single cell, in a high current 18650, especially so.
Any wonder why airlines have such "heavy" regs on the carriage of bulk li ion batteries.
Hope you found this interesting.
Mike.
PS laptop batteries usually have 6 or 8 of these batteries in series solder tagged and encased in a plastic shell.
USB powerbanks are another application where 18650s are used.
