Why Does The Samsung Galaxy Note7 Blow Up

Samsung has thrown in the towel. As you may have heard by now, Samsung has stopped production, sales, and exchanges of the Galaxy Note7, permanently. They are now organising a global recall. Samsung had said previously that they were investigating the continuing fire incidents plaguing the replaced devices, but we’ve not yet heard of any findings.

Now, it may be that the second recall and the termination of the Galaxy Note7 was made purely for safety reasons, regardless of their ongoing investigations.

Or, and I think this more likely, that Samsung has a pretty good idea of what might be wrong, and has come to realise that they have a fundamental problem that they are unable to solve, or at least not practical to solve at this juncture, and that cancelling the entire Galaxy Note7 is the best course of action.

What exactly is wrong with the Galaxy Note7?

In the first round, Samsung said they identified anomalies with battery cells from their subsidiary, Samsung SDI, one of the two suppliers of batteries used in the Galaxy Note7. A “very rare manufacturing process error” put pressure on plates within the battery cells, which then caused the anode to come into contact with the cathode. This resulted in a short-circuit, which led to overheating and then fire.

Batteries from the other supplier was alright, or at least that’s what we learn from then. The manufacturing anomaly was only with Samsung SDI. Simply switching the batteries should have resolved the problem.

It didn’t. If the problem is still about batteries, then the problem isn’t just with Samsung SDI then, since Samsung SDI batteries were no longer used in the replaced Galaxy Note7 devices.

I am no battery expert, but I have my theories.

There are many things every smartphone manufacturer wants to do with their devices. Two common themes are: longer battery life (i.e. higher capacity battery), and thinner/smaller device. The two goals run against each other. The higher capacity battery will necessarily need more space. Reducing space means you need to sacrifice battery capacity.

But perhaps you could optimise the battery design, by making it thinner than it should normally have been designed, perhaps by lessening the amount of insulating materials, or using thinner types of insulating materials? Perhaps, indeed, there is even a way during manufacturing to “compress” the battery more tightly?

My speculation is that Samsung has designed the Galaxy Note7’s batteries to be different.

Let’s take a step back and look at the Galaxy Note7 versus the Note5 in terms of some of their key specs.

The Note5 is a similar 5.7-inch display phablet. It has physical dimensions of 153.2 x 76.1 x 7.6 mm, or 88605mm³ of volume, and has a 3000mAh battery. The Note7, on the other hand, has physical dimensions of 153.5 x 73.9 x 7.9 mm, or 89615mm³. It is smaller in height and width, but slightly thicker, for an overall 1% increase in volume. It’s battery capacity, however, has increased tremendously to 3500mAh.

Now, is it possible that the Note7 internals have been rearranged somewhat so that there’s more space for the battery? From what I can gather from iFixit’s teardown of the Note5 and Note7, it doesn’t look like the battery space has changed much. Of course, this isn’t at all an accurate assessment, at least not unless you physically teardown the devices to measure them yourself. (Admittedly, the Note7’s batteries appear longer, though narrower, than the Note5, so casual visual comparison is difficult.)

However, do you notice how malleable the battery appears to be in the Note7 teardown? Take note of iFxit’s comment:

Curiously, the Note7’s battery is fortified by walls carved from the rear case, providing extra structural integrity, and maybe even some water protection.

The walls of the rear case provide structural integrity for the battery!

The Note7’s increase in thickness (7.9mm vs 7.6mm, or about 4%) doesn’t explain the battery capacity increase (3500mAh vs 3000mAh, or about 17%).

So, indeed, my speculation is that on the Note7, Samsung has somehow squeezed more capacity out of the (roughly) same battery space.

Something has to compromise. Somewhere. Perhaps, they broke some rules with the norm or best practice in battery design or construction. What may look workable on paper, may not translate well into manufacturing, or real world usage in the hands of consumers. They hadn’t done enough testing, because they were on a tight deadline to beat the iPhone’s 2016 launch date. (For good measure, they even skipped the Note6 in their mad rush…)

That’s, of course, just my guess. I’m no battery expert. If it were only the problem with battery, Samsung could possibly salvage the situation by replacing the batteries yet again, perhaps this time with something of less aggressive capacity. Would this have helped?

Doing that would clearly giveaway the fact that Samsung had been too aggressive with the Note7’s specifications and compromised consumer’s safety. That’s no good for marketing and image. Downsizing the replacement’s capacity is also bad for marketing, since it would diminish runtime, which I’d expect would end up worse off than it’s predecessor.

It could be worse. Perhaps something else with the phone had to be redesigned. Something fundamentally so drastic that Samsung felt was better to cancel the Note7 than to fix it.

Another thought is that Samsung could have weighed all the options, going forward, available to them, and saw the cancellation as the best commercial solution. Their image has been tainted, A recall and product cancellation would be extreme, but it would appear brave and bold. It would be courage.

Kicking out the headphone jack isn’t courage. Not launching a new iPhone this year would be courage. Cancelling one’s flagship product would be even more courage.

These are complicated options to consider, and so it’s no wonder that while Samsung had been quite forthcoming in the initial recall, things have developed much more slowly this time around. The major US carriers had their own stop-sales and replace-with-some-other declarations before Samsung made their own announcement.

I hope Samsung will let us know what’s really wrong with the Galaxy Note7.