 Today's phones are miracles of modern technology. They can stream Netflix, play incredible video games, and connect us with people around the world at any time, all in the palm of our hands. So how come the battery life sucks so much? You remember your old phone, the one that just played snake and made calls? Those things had batteries a fraction of the size of our modern smartphones, but somehow they lasted a week. So with all the leaps and bounds we've made in modern technology, why can't our current phones just last until the end of the day? To find out why our batteries are so bad, I talked to Dr. Venkat Srinivasan, an expert in battery technology. So I mean, part of this is obviously, as you know very, very well, the demands of the app, I mean, of the mobile devices increased dramatically, right? I mean, there was pre-touch screens, pre all of us on Twitter and Instagram and taking pictures and getting on these high-resolution screens. So much of it is just the fact that the draw has become dramatically more. Okay, so phones have gotten way better and they need more power because of that. An original Nokia 3310 had 100 megahertz single-core processor and a 4,000 pixel display. A Galaxy S10 Plus from 2019, on the other hand, has a 2.4 gigahertz eight-core processor that pushes 4,377,600 pixels. So yeah, things have come a long way. For processor speed, we even have a rule for this called Moore's Law, which says that roughly every two years, the number of transistors that we can fit on a single microtrip will double, which means proportionally more powerful computers and phones. We all talk about Moore's Law for electronics. Unfortunately, battery energy densities don't scale at the same rate as Moore's Law is scaling. Turns out batteries have been evolving. It's just at a different pace in which things happen. So while batteries don't improve as fast as the rate of the rest of our phones, they have been improving to a point. We've been squeezing out more and more power from materials and the technology that we have now, but there are limits to how far we can go. A lot of what has been happening for a long time has been sort of shrinking all the devices that are in the, in the, in sort of the chip to make things better and better and better. In a battery, the equivalent of that would be I'm removing, you know, unwanted stuff from the battery so that I add more and more and more dense, energy-dense material so that I can ultimately pack in a lot more energy into the system. Turns out we've been doing this game for the last 20 years. And if you do this game for the last 20 years, you start to reach a point where it's very difficult to squeeze out any more stuff. Pretty much most of the battery today is being used for something. Our modern batteries basically use up all the internal space they have for power. And the only way to get more is by shrinking down those internal parts, like the barriers between cells. And when those get too thin, that's where safety issues can happen. And when things get pushed too far, well, we get products like the Galaxy Note 7. Basically, in modern lithium-ion batteries, energy transfers between the positive and negative electrodes through a liquid solution. Now, that solution's flammable, but it's okay because there's a separator between the electrodes. In the Note 7, that separator was too thin, it sparked, and then the liquid caught on fire. What happened five years ago was that when it became clear that these limits were getting hit, right, where we couldn't remove any more things, but we've reached a stage where new improvements in energy density are gonna come from changing battery materials, and new materials are always slower. So what does the future look like? Well, right now, the material we use is called lithium cobalt, a battery technology that we've been using since the early 90s. But researchers have already started work on what comes next. Today, all the batteries have a liquid electrolyte in them. The next big thing, and I think this is gonna be a huge thing, is solid-state batteries. It's things that don't have liquids, but are solids that can conduct lithium back and forth between them. You can't predict a breakthrough, so you don't know when it's gonna happen, but we think that's where things are going. And if that happens, cell phones and laptops will start getting more energy dense. There is one slight issue that could come up, though. By the time better batteries do come around, our phones might be even more powerful than they are right now, which might leave us right back where we started, with less than a day of battery life and external batteries galore. Progress always has a price. Thanks so much for watching. For more great videos like this, make sure to like and subscribe to The Verge. And if you want to learn more about phone batteries, check out this video about overcharging them.