According to the Youtuber JerryRigEverything the Samsung Galaxy Note 7 explodes because of the failure of a small circuit board at the top of the battery during charging. Jerry Explains that while charging, the tiny regulator doesn’t do its job and the battery enters into a thermal runaway and the voltage regulator can’t stop the chain reaction thus it explodes. Watch out the video below to understand the whole process.
Jerry Explains why the Samsung Galaxy Note 7 battery explodes
Below is the whole transcript of the video if you are on a tight data plan, to understand the process better, it is better to watch the video.
Rechargeable Lithium-ion batteries are everywhere – Electronics, tablets, laptops, cars and pretty much every single cell phone. And most of the time, these lithium batteries are incredibly safe. As long as the lithium fail-safes are in place. Fail-safes… that work. Samsung just, voluntarily, recalled an estimated 2 million Galaxy Note 7’s as a safety precaution. Since some of the batteries are exploding inside the phone. Obviously, random explosions are not a feature that most people look for when purchasing a cell phone. So let’s take a look at the Note 7 and assess why it might spontaneously combust.
During charging, the phone is protected by multiple fail-safes. First off you have the part the plugs into the wall; the charger, and the cable. If the charger is faulty, or not designed specifically for the phone, it can affect the safety of the battery. It can destroy the battery’s protection circuit which I’ll show you in a second. The charging port is also a fail-safe as well. It tries to do its best to protect the phone and the battery from faulty chargers and incorrect electrical flow. BUT as a last resort, the battery also has its own fail-safe built in. Here is where the battery plugs into the motherboard to receive its juice and supply the phone power. Then we have this circuit board; also called the protection circuit, at the top of the battery. This controls the flow of electricity AND the temperature of the lithium. All lithium batteries should have a variation of this board. It makes sure that the battery does not overcharge, and it has a thermal fuse of sorts will blow if the temperature gets too hot, thus protecting the lithium inside from rapid unplanned catastrophic disassembly.
The body of the battery is typically two layers. The Anode and the cathode, which are separated by an electrically conducting fluid. This is oily and smells surprisingly of burnt skittles. The combination of these elements allow your phone to charge and function as long as the battery protection circuitry is working correctly and the electricity and temperature of the lithium are regulated. If it is not regulated correctly during charging, the lithium will react violently. So if we look at one of the exploded phones… we can easily see which of the fail-safes… is failing at being safe. The charging port sits here inside of the phone. There are no burn marks near the port, OR where the port connects to the motherboard. BUT we do see some scorching where the battery sits. Not where it plugs into the main board which would be about here. But it explodes in the center of the battery. Around the battery hole in the thick aluminum midframe. So on this particular exploded Note 7, all of the connections are good, it’s just the battery itself isn’t behaving.
Tesla cars are also powered by lithium batteries, and the Model S had a small issue at the beginning of production where the batteries on the undercarriage could get punctured by derbies on the road… which could cause the lithium battery under the car to explode. Tesla corrected this problem by adding a titanium puncture proof under-plate to the Model S. The Note 7 batteries are definitely not being punctured internally. Since there is nothing to poke them on the inside as you can see from my teardown video. It sits on smooth aluminum. So since the Note 7 battery isn’t being punctured… that narrows us down to overcharging, shorting, or impurities in the battery itself. A small metal impurity in the lithium could short it out.
Personally, I think the problem has to do with the little circuit board failing at the top of the battery during charging. From what I have read about the people who have complained publicly about their Note 7 exploding, the phone was charging when it happened. The phone starts charging… the tiny regulator doesn’t do its job and the battery enters into a thermal runaway and the voltage regulator can’t stop the chain reaction. Since this particular Note 7 battery isn’t plugged into the phone right now, my tweezers are acting as the other possible failure point; a metal impurity in the manufacturing of the battery; That could possibly short out the battery. All of this smoke and fire would be under extreme pressure locked inside of your water tight Note 7, the more pressure there is.. the bigger the explosion. Remember this only happens on a VERY SMALL number of devices. So far it’s only happened on 35 phones out of 2 million. So, ya definitely take advantage of the recall, but also feel free to use your phone as normal in the meantime…. just don’t set it on your lap while its plugged into the wall…. and maybe take a fire extinguisher with you to bed… just in case.