The Pixel 4's power-plunging puzzle

There may be more to the Pixel 4 stamina story than what we see on the surface.

Pixel 4 Standby Power
Google/PublicDomainPictures/JR Raphael

Fountains of virtual ink have been spilled over the Pixel 4's stamina and how the phone's battery life isn't all that it could be.

Me? After living with the Pixel 4 for a few weeks now, I'm not quite as down on its staying power as some folks were whilst working up early reviews of the device. I think somewhere between "okay" and "borderline acceptable" sums up my experience with the phone's endurance thus far: I'm consistently making it through what I'd call full typical days for me, at this point, but I'm sometimes cutting it closer than I'd like by the end of the day — something that certainly doesn't inspire confidence about how the phone might fare when I'm traveling or having another sort of day with unusually high usage.

I've heard from quite a few folks who bought the Pixel 4 and are having similarly adequate experiences in the stamina department — part of the inevitable variance that comes with battery life, given the differences in how we all use our phones, and perhaps also the effect of Android's Adaptive Battery system kicking in as the software starts to optimize its power consumption — but still, I don't think anyone would describe the device's battery life as exemplary. And I'd say there's little real question that it could, and arguably should, be better.

Well, something came to my attention with the phone's power-related performance this week, and I can't help but wonder if it's at least part of the problem.

It's all about the Pixel 4's standby power consumption — the way the phone burns through battery life when it's idle and you aren't actively using it. And it's really quite baffling.

Since 2015's Android 6.0 Marshmallow release, y'see, Android has had a power management system called Doze in place. Doze is designed to make sure your phone uses the absolute minimum amount of power required whenever it's unplugged, completely still, and with its screen off. It basically puts your phone into a deep sleep when it's idle and allows only critical, high-priority tasks to take place.

When Doze first came around, the difference was incredible. Instead of losing a considerable amount of power overnight, phones were suddenly shedding little to none of their charge during those unused hours. You could set your phone down before going to bed and then wake up to find it with almost the same percent of power as when you left it — or maybe with a drop of a point or two at most.

With the Pixel 4, I've been seeing the phone drop by as much as 16 percentage points while it's sitting completely still and unused overnight. That, suffice it to say, is a massive loss of battery life — a drop reminiscent of the pre-Marshmallow, pre-Doze days. And most vexing of all, it seems to be happening for no valid reason.

My observations with this certainly aren't scientific, but they've been remarkably consistent across several days and two different Pixel 4 devices I've been using. And my setup on the phones is quite standard, without any unusual apps or anything (even Facebook) that'd logically be keeping the system awake. I keep the Always-On Display option deactivated, which means the screen is completely dark and inactive during the overnight hours. What's more, when I look at the specific breakdown of what apps and services consumed battery power during that period, the only item that ever shows a meaningful increase in usage from night to morning is "Phone idle," which usually goes up by a few points during the night. "Android System" and "Wi-Fi" both also typically bump up by a single percentage point each. Nothing else changes.

Just to be thorough, I tried checking this on a few nights with a Pixel 4 that had been freshly factory-reset, had barely been used, and had nothing on it other than the default apps that came preinstalled on the phone. The drop was slightly less extreme on that device but still significantly more than you'd expect to see in a post-Marshmallow, Doze-enabled world, with the phone losing 8 to 13 percentage points while sitting unused overnight.

And while this isn't the type of thing most people would pick up on, signs suggest I'm not the only one. I've heard from a few Pixel-4-owning readers who have experienced similar levels of overnight power loss with the device. A search of the XDA Developers forum — a website popular with Android enthusiasts — also turns up multiple reports of similar behavior, as does a perusal of Pixel-related sections of Reddit. All considered (and particularly with the factory-reset, no-apps-added phone in the mix), it's enough to make it seem like more than just a fluke thing or a setup-specific anomaly.

Oh, and one more thing: For further comparison, I took the same night-to-morning battery measurements with my wife's Pixel 3a phone (which, in case you were wondering, earned me an exasperated sigh along with the now-standard "What are you doing to my phone now?" response). Her phone saw a drop of only 3 percentage points during the same time period — a number that's more in line with what you should see from a Doze-enabled Android device.

Now, I know what you must be thinking: This is surely all because of Motion Sense — the Pixel 4's radar-based hand gesture system — right? That certainly seems like a logical conclusion; after all, the radar chip is always watching for movement around the phone, so it's only sensible that it could eat away at power even when the phone isn't in use.

I thought that might be the case, too, but I tested the Pixel 4's overnight power drop with Motion Sense completely disabled — and guess what? Absolutely no difference. The phone experienced the exact same drop for me, with or without the radar system running (a 16-point decrease on two consecutive nights with the same number of hours and the presence of Motion Sense acting as the only distinguishing variable). That makes it seem pretty clear to me that Motion Sense isn't a meaningful factor in the Pixel 4's idle-time power consumption.

But it also seems pretty clear to me that something funky is going on — and that the Pixel 4 is losing more power than it oughta be when it's resting and inactive. And it's hard not to wonder if that same pattern might, on some level, also be responsible for the accelerated depletion the phone seems to experience during the day. I've often noticed that the battery life falls a surprising amount even when I'm not actively using it — like just now, when I set it down on my desk and didn't touch it for 90 minutes, and yet the battery level had dropped by 3 percentage points by the end. Not a single app or service had been active, and the only items in the battery stats that had any form of elevated usage were "Android System" and "Phone idle." I saw similar results when repeating that experiment with the just-reset, almost-nothing-on-it Pixel 4 as well. What's going on?

I reached out to Google early this week to see if anyone could offer an explanation or even an assurance that, yes, something seems to be amiss and that a software update could resolve this. The company has been looking at bug reports that I captured and submitted and thinks the problem may be at least in part related to something peculiar happening with the phone and the Google Cast system, as one of the devices was evidently kept awake by a curiously high amount of inexplicable Cast-related activity during the night. I'll update this page if I receive any additional info.

For now, it seems safe to say that something is up with the Pixel 4's standby power consumption — something that's absolutely affecting the phone's overnight stamina and quite possibly affecting its overall staying power to some degree as well. The issue may or may not be limited to the Pixel 4 — and it may or may not be affecting all Pixel 4 units — but given my observations and the observations from others noticing similar patterns, it sure seems likely that there's some connection. (And we know, at the very least, that the Pixel 3a doesn't appear to be affected.)

If it's something that Google can pinpoint and resolve, the Pixel 4 might just go from being "okay" to being "pretty decent" with stamina, at least for people like me whose usage isn't exceptionally demanding.

Pixel phones have a bit of a reputation for being rough around the edges in their first couple months of existence and then getting smoothed out and more commendable after a round or two of fixes. Let's see if the Pixel 4 and its stamina saga follow that same pattern — or if the device's current level of staying power is simply as good as it gets.

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[Android Intelligence videos at Computerworld]

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