Samsung Has Discovered What Is Causing The Note 7 Battery To Explode

DroidModderX

Super Moderator
Staff member
Premium Member
Joined
Oct 6, 2011
Messages
5,782
Reaction score
2,133

In a Q&A posted to Samsung's UK website Samsung has decided to provide some details in regards to what exactly is causing the Note 7 battery to explode. They aren't exactly calling this a recall. When asked "Is this considered a recall?" Samsung answered, "Although this is isolated to a battery cell issue, we are prioritising the safety of our customers first so, we are voluntarily replacing Galaxy Note7 devices with a new one."

Samsung has found during investigation that a battery cell issue causes overheating when the anode to cathode comes into contact. According to Samsung this is a very rare manufacturing error. As of September 1, 35 cases of exploding batteries have been reported, 17 in Korea, 17 in the US, and 1 in Taiwan.

via Samsung
 

FoxKat

Premium Member
Premium Member
Joined
Apr 2, 2010
Messages
14,651
Reaction score
4,703
Location
Pennsylvania
Current Phone Model
Droid Turbo 2 & Galaxy S7
For the layperson, this means the battery is shorting internally, commonly called a internal shunt. When this happens, the battery dumps its fill load of current across that short and temperatures internally skyrocket, much the same as a space heater does when plugged into an AC outlet. Shorting across a power source creates a complete circuit and essentially becomes a miniature arc welder or heating element. In home electric wiring, a short can burn your home down (as did mine on December 12, 2015).

This can happen from several causes. It can be due to excess compressing, folding, bending or puncturing the battery. It can also happen during manufacture, when as one of the last steps before the battery casing is heat welded shut, the electrolyte - the Lithium paste is injected between the folds of the battery sheets, but doesn't coat them completely. Then when the battery is sealed and compressed flat, the two internal "poles" of the battery, the Plus and Minus poles, if you will, come in contact or are close enough that an internal shunt can be created easily through normal charging.

These internal shunts can also happen when the battery is charged improperly. This is one reason why the charging process of the batteries are so critical and they are so carefully monitored and administered. In the case of these phones, the issue is related to charging, so I suspect it's maybe not so much a battery issue as an actual charging issue. This is also one of the reasons I tout so strongly that you use only the charging adapters and cables supplied by your phone manufacturer or the ones sold by the carrier who markets and sells your phone.

Also as many know, I'm an advocate of only using Rapid/Quick/Turbo charging when necessary. In other words if the phone is going to be idle for hours anyway, why subject the battery to undue stress to charge it rapidly. I use my old Droid MAXX chargers to gently charge my Turbo 2 overnight, and only Turbo charge if I'm in the car or home for brief periods of time before being away from a power source for extended periods of time.

I'm wondering if maybe there is a flaw in the charging. With these phones being forced to charge faster and faster, the risk of batteries developing internal shunts grows higher. Then you have a few batteries that may have marginal electrolyte coating and what you have is the perfect storm.

In this case, they claim these batteries (some of them), have apparently suffered some serious flaw in manufacture and this contributes to some (a very small percentage), failing while charging. It is a very dangerous risk and nobody should be continuing to charge these phones against the manufacturer's advice. Instead, when you are able, take them, in a metal container to the nearest dealer for exchange/replacement. Using them may be OK, but under no circumstances would I charge them.
 
Last edited:

jpiarull

Active Member
Joined
Sep 3, 2010
Messages
235
Reaction score
66
Location
NJ
Current Phone Model
Moto Z Force Droid
Twitter
jpiarull
For the layperson, this means the battery is shorting internally, commonly called a internal shunt. When this happens, the battery dumps its fill load of current across that short and temperatures internally skyrocket, much the same as a space heater does when plugged into an AC outlet. Shorting across a power source creates a complete circuit and essentially becomes a miniature arc welder or heating element. In home electric wiring, a short can burn your home down (as did mine on December 12, 2015).

This can happen from several causes. It can be due to excess compressing, folding, bending or puncturing the battery. It can also happen during manufacture, when as one of the last steps before the battery casing is heat welded shut, the electrolyte - the Lithium paste is injected between the folds of the battery sheets, but doesn't coat them completely. Then when the battery is sealed and compressed flat, the two internal "poles" of the battery, the Plus and Minus poles, if you will, come in contact or are close enough that an internal shunt can be created easily through normal charging.

These internal shunts can also happen when the battery is charged improperly. This is one reason why the charging process of the batteries are so critical and they are so carefully monitored and administered. In the case of these phones, the issue is related to charging, so I suspect it's maybe not so much a battery issue as an actual charging issue. This is also one of the reasons I tout so strongly that you use only the charging adapters and cables supplied by your phone manufacturer or the ones sold by the carrier who markets and sells your phone.

I'm wondering if maybe there is a flaw in the charging. With these phones being forced to charge faster and faster, the risk of batteries developing internal shunts grows higher. Then you have a few batteries that may have marginal electrolyte coating and what you have is there perfect storm.

In this case, they claim these batteries (some of them), have apparently suffered some serious flaw in manufacture and this contributes to some (a very small percentage), failing while charging. It is a very dangerous risk and nobody should be continuing to charge these phones against the manufacturer's advice. Instead, when you are able, take them, in a metal container to the nearest dealer for exchange/replacement. Using them may be OK, but under no circumstances would I charge them.
I agree with you 100% here with the risks & dangers of overuse of quick-charging devices. For my Moto Z Force Droid I primarily use my OEM Motorola Droid charger from 2010, as it's low amperage and never makes the phone feel hot to the touch. Phones themselves today do not have a whole lot of surface area to act as a heat sink to dissipate heat away from the battery and motherboard; consequently, manufacturers are forced to make these things thinner and thinner due to customer demand. There is a limit between good looks and functionality, in this case consumer safety. I just hope this will serve as a major lesson across the entire Mobile & Telecom industry, not just for Samsung. Hopefully now with the FAA ban temporarily, people will understand and catch on that thinner is not better.

Sent from my XT1650 using Tapatalk
 

FoxKat

Premium Member
Premium Member
Joined
Apr 2, 2010
Messages
14,651
Reaction score
4,703
Location
Pennsylvania
Current Phone Model
Droid Turbo 2 & Galaxy S7
I agree with you 100% here with the risks & dangers of overuse of quick-charging devices. For my Moto Z Force Droid I primarily use my OEM Motorola Droid charger from 2010, as it's low amperage and never makes the phone feel hot to the touch. Phones themselves today do not have a whole lot of surface area to act as a heat sink to dissipate heat away from the battery and motherboard; consequently, manufacturers are forced to make these things thinner and thinner due to customer demand. There is a limit between good looks and functionality, in this case consumer safety. I just hope this will serve as a major lesson across the entire Mobile & Telecom industry, not just for Samsung. Hopefully now with the FAA ban temporarily, people will understand and catch on that thinner is not better.

Sent from my XT1650 using Tapatalk
Brilliant observations. You may know me as a staunch advocate of gently charging whenever possible. The reference to heat dissipation is also a very valid point.

These phones get HOT while charging, mostly heat from the battery itself, and the materials they are made from on the exterior, mostly plastic, material and glass for the screen are not good conductors of heat. The battery is held in place by double sided tape (a thermal insulator), add to that a screen protector which has adhesive (another thermal insulator), and you have essentially created a heat containment unit. In the case of the Turbo 2, the screen is 5 layers of laminate and with each layer it creates another barrier to heat conductivity, some being plastic which are terrible heat conductors, so it further contains the heat inside.

On my Turbo 2 I have yet another layer, a tempered glass screen protector in place so it's six layers of thermal barrier for mine (really upwards of twelve if you consider the adhesives as their own layers). Add a case, soft shell, or a double soft/hard shell case like the OtterBox and you're insulating even more. Then your hands are a terrible heat conductors, actually serving to help contain the heat. Next, most people place them in our pockets or in pocketbooks or purses, hot and with no ventilation. Finally, charging in a car often subjects them to elevated internal temperatures and let's not forget direct sunlight! When you really start to think about the environment we place these batteries in, and then we heat them up, it's no wonder there are failures due to thermal runaway.

Sent from my XT1585 using Tapatalk
 
Last edited:

jpiarull

Active Member
Joined
Sep 3, 2010
Messages
235
Reaction score
66
Location
NJ
Current Phone Model
Moto Z Force Droid
Twitter
jpiarull
Brilliant observations. You may know me as a staunch advocate of gently charging whenever possible. The reference to heat dissipation is also a very valid point.

These phones get HOT while charging, mostly heat from the battery itself, and the materials they are made from on the exterior, mostly plastic, material and glass for the screen are not good conductors of heat. The battery is held in place by double sided tape (a thermal insulator), add to that a screen protector which has adhesive (another thermal insulator), and you have essentially created a heat containment unit. In the case of the Turbo 2, the screen is 5 layers of laminate and with each layer it creates another barrier to heat conductivity, some being plastic which are terrible heat conductors, so it further contains the heat inside.

On my Turbo 2 I have yet another layer, a tempered glass screen protector in place so it's six layers of thermal barrier for mine (really upwards of twelve if you consider the adhesives as their own layers). Add a case, soft shell, or a double soft/hard shell case like the OtterBox and you're insulating even more. Then your hands are a terrible heat conductors, actually serving to help contain the heat. Next, most people place them in our pockets or in pocketbooks or purses, hot and with no ventilation. Finally, charging in a car often subjects them to elevated internal temperatures and let's not forget direct sunlight! When you really start to think about the environment we place these batteries in, and then we heat them up, it's no wonder there are failures due to thermal runaway.

Sent from my XT1585 using Tapatalk
Boeing has this issue still with the 787 composite jet as they've had incidents of thermal runaway with lithium ion batteries powering vital systems on board. Fortunately has not resulted in fatalities, however it should call into question the safety and reliability of lithium ion batteries for these reasons alone.

Sent from my XT1650 using Tapatalk
 
Top