Battery for smartphones, which can last a few weeks.

This is the Energizer P18K Pop Smartphone… yup, a smartphone. With an 18,000mAh Li-ion battery, it offered 50 days of cellular standby time. Based on a mid-range MediaTek Helio P70 SOC and a moderate LCD resolution of 1080 x 2280 pixels, you might expect it to make it two weeks on a charge. My ZTE Axon 10 Pro manages a typical 3 days from a 4000mAhr battery, more DRAM, and a higher-end processor. That’s certainly brute-forcing it, but what other option do you have?

This one, however, is real. This is the Blackview BV9100, which sports a 12000mAh built-in battery (labelled 13000mAh, but 12000mAh in testing), with 30W wired charging, in a rugged case. They sell this as an “outdoor smartphone.” It’s running the MediaTek Helio P35 processor, a low-end 8 core processor, all cores ARM Cortex A53, along with 4GiB RAM (LPDDR4X) and 64GB flash (eMMC). So certainly usable, and available for about $250. While not terribly obvious from the photo, this phone is 19.45mm thick and 408g. Not as barking mad as the Energizer phone, but you’re going to know you’re carrying this one, and it’s probably more at home in cargo pants than skinny jeans. But speaking of skinny jeans, an iPhone 11 Pro is, by comparison, is 8.1mm thick and 188g.

You’re relatively in luck if you want one of these for use on AT&T or T-Mobile, at least in the USA. Previously, most of these specialty rugged Chinese phones from Blackview, Ulephone, Umidigi, etc. were only available as international models. So you didn’t have most of the recent LTE bands, and your 4G performance would suffer. I did a quick check of the BV9100 and it seems to have all of the T-Mobile bands, a big improvement. This is always a thing to check, even if you’re just picking up a phone like this to take on hikes, to music festivals, all those things we did before the lockdown that threatened an everyday phone on battery life and, well, the survival of a $1,000+ phone in a harsh environment.

But rather than get crazy, this can be solved in part by design, but only in part. My Honor Magicwatch 2 last around 1.5–2 weeks on a charge, which isn’t bad given that quite a few smart watches don’t last a full day. How do they do this? Well, part of it’s the same idea as the Energizer — it’s got a battery that’s twice the size of that of some other smartwatches. Though not so huge it’s noticably larger than the type of watch I used to wear, well, back when people wore plain old watches. It doesn’t run WiFi or cellular. It has a much lower power, lower performance processor than an Apple Watch, and it’s running a set of apps defined by Honor/Huawei, not any 3rd party apps. So in one sense it’s limited. But in another, it’s way more useful simply because what it does, it does usefully long enough that I can rely on it working, rather than always needing a charge. So some of it’s correctly defining the scope of the device.

That approach is more or less taken on the HiSense A5, a so-called “reading smartphone.” This phone swaps out the typical OLED or LCD display for a 1440 x 720 monochrome e-paper display. It runs a low-end Snapdragon 439 processor and includes a largeish 4000mAh battery. You’re not going to get useful video on-screen, web pages might rending rather dubious, etc. But you might see close to two weeks battery life from this one, in part due to the big battery and display, in part due to the fact you can’t burn power on video or complex games with much success.

But if you’re asking for a thin, flagship-spec phone with a two-week battery life, you can’t have one. Battery technology for such a thing hasn’t been invented yet, and simply may never exist.

That doesn’t mean someone’s not trying to deliver a better battery. But these things tend to take decades to get right. The next one up might be the graphene battery. Samsung has been working with “graphene ball” battery technology that would mean 12 minute full charging (as of their latest specs) and maybe a 60% longer run time for the same battery size. However, this is still a li-ion battery, just with their current carbon-over-silicon anode replaced by a graphene ball anode. That still doesn’t get you your 2-week phone in a normal smartphone size, but maybe Energizer would take another crack at it!

Unfortunately, the Internet has a collective ability to embue every unreleased technology with all of the things everyone wants it to offer. So you may read of graphene or some other battery maybe delivering a month’s phone operation. You may also be lead to belive that a graphene battery is something fundamentally new, rather than just a tweak of the li-ion receipe, much as your “LED” or “Quantum Dot” monitor is still an LCD monitor, just with a few tweaks. Don’t count on big change, because fundamentally different battery chemistries are only rarely achieved. Li-ion batteries were theorized in the 1970s and built at the lab level by the mid-1980s. This is very different than the rest of the phone technology, based on the evolution of chip architecture. Next year’s phone gets faster just because we do the same exact thing as this year’s phone, just with another year of design technology under our collective belt, and maybe a smaller transistor size.

And real progress means several things all at once. Lower power displays have helped, whether an e-paper display or an OLED display in a dark theme. But can you live with that? 5G-NR promises a lower power, higher performance radio, but it’ll take another generation or two to get there, just as LTE has delivered lower power, higher performance over 3G, but it took a few generations of chips. Memory and CPU technology delivers better power for the same performance in each generation, but we generally ask for more performance at the same power consumption, more or less, so a real demand for long running phones has to materialize and drive development in that direction. We’ve seen special functional units, GPUs, DSPs, ISPs, Neural Processors, etc. lower the power it takes a smartphone (or other computer) to do the same work, but we rarely ask it to only do the same work it did last year.

In short, most folks are pretty much okay with a phone that needs to be charged every night. The things necessary to extend battery life, even with better batteries, are not going to be all that generally popular if they come at the cost of features. Faster charging and longer battery longevity would be easy wins, but I suspect a higher capacity battery just gets used by most companies to do more work at the same battery life. Especially considering how much faster electronics moves than the chemistry-based battery technology.