Changes coming to Chrome OS could help the Samsung Galaxy Chromebook battery life issues

There’s no denying the brilliance of the Samsung Galaxy Chromebook. Even if you’ve never had a moment to get your hands on one, trust me when I say that this Chromebook is superlative in nearly every facet. Only days into the full review process, there are still things I’m working through to form my overall thoughts about this next-gen Chromebook. There’s simply a lot to like in this package and I’m not shy about saying that. It is expensive, though, and that means I instinctively demand more from this Chromebook than nearly all that have come before it.

In that vein, I’m bothered by the battery life like many of you who’ve read reviews are. Compared to other Chromebooks, it isn’t great, but there could be some hope on the horizon if you’re still intrigued by this fantastic piece of kit. I can’t guarantee what sort of difference these changes will make, but I can tell you work is being done that should help mitigate some of the existing concern around the battery longevity.

First, let me say this: in my previous post about this Chromebook’s battery, I made some points about the display and how power-hungry it is both from a brightness and pixel-density standpoint. This thing can absolutely devour your battery if not used properly. That part of this whole equation won’t be changing anytime soon. The screen is a standout feature that possesses great abilities and must be used with a similar measure of caution. Coming in at a whopping 750 nits at max brightness, you and I need to realize that there aren’t many situations where 100% brightness on this device is warranted or necessary. Keeping that brightness down goes a long way to help in an already bad situation.

But, there are other factors at play here. I spent a good bit of time yesterday running test after test, comparing the Galaxy Chromebook to the Pixelbook Go and the ASUS Flip C436 in an attempt to rule out the idea that something other than the display was to blame. After tons of tests, battery drains, and multiple scenarios, one thing was very clear: there is another culprit working in tandem with the screen to decimate battery. That culprit? The processor.

Again, not ground-breaking stuff here, but it completely escaped me yesterday during my testing that many of the thin, light devices we’ve had great battery from in the past are all powered by Y-series Intel chips. The Pixelbook, Pixel Slate, Pixelbook Go, ASUS Flip C436, Flip C433, and C425 all had great battery, kept the chassis thin, and did so partly because of the Y-series TDP (thermal design power) is only 5W versus the 15W of U-series processors. TDP is Intel’s measure of power consumption under the maximum theoretical load, so as you can easily piece together, 15W TDP is going to drain the battery more that 5W TDP every time.

Taking this higher power drain in combination with the high power consumption of the 4K AMOLED screen and you have a recipe for fast battery drain. The 48 Wh battery inside the Galaxy Chromebook isn’t tiny, but it isn’t huge, either. For reference, the Pixelbook Go 4K model bumps things up to a 57 Wh battery and devices like last year’s HP Chromebook x360 G1 packed in a 60Wh battery to go along with it’s U-series chip and was a battery champ. So we have a power-hungry processor, power-hungry display, and a average sized battery. Things aren’t looking good, but there’s a change coming that could help mitigate this a bit.

Enter the Governor

If you aren’t familiar with the idea of a governor, we’re not talking about a political office. Instead, the idea is the same as what you see in go-carts and cars where the throttle is physically limited and the vehicle can only hit a regulated top speed. In the software world, Mac OS and Windows have both had this for years and our other mobile tech gets the same treatment with things like battery saving mode.

The idea is simple: to conserve battery, pump the brakes on the processor a bit to keep more juice in the tank for later. We’ve had governors in place on Chromebooks in the past, but not quite like what we’re seeing being added for the ‘Hatch’ line of Chromebooks and, more specifically, ‘Kohaku’ (a.k.a the Galaxy Chromebook). There are a ton of commits around getting this added and nearly all of them have already been merged, but here’s the prevailing language from those changes:

chipset-cml: Add power governor selection feature

This patch adds the feature of setting scaling_governor to performance on AC else set it to powersave governor.

This improves performance of the device on AC. Used udev rule to implement this functionality.

# If AC is plugged in, change the scaling_governor to performance.

# If AC is unplugged, change the scaling_governor to powersave.

As you can see, a new governor is being added to the Comet Lake (CML) chipset to change the CPU performance between the plugged-in and not-plugged-in state. This will allow the Chromebook to flex all its muscle on the charger and back things off when on battery. The Comet Lake Core i5 in this machine has plenty of headroom, so this move will surely help the battery last quite a bit longer when you’ve come off the plug.

It is unclear at this point if users will be able to manually change this option on the fly, but I hope that will be the case. In most scenarios, you don’t need 100% processor power when on the move, but there will be times it is helpful. Being able to force performance mode even when on battery would be a thing most users would find very handy, so I’m hopeful that as this change comes, the Chrome OS developers give us the option. After all, in all the other scenarios where our hardware leverages a governor for us to save battery, we always have the option to turn that setting off if we choose to, so I’d hope Chrome OS wont’ be any different.

Shop Samsung Galaxy Chromebook at Chrome Shop

Turn That Screen Down

Secondly, I know I am guilty of keeping my screen brighter than I need on a regular basis. I like bright, vibrant visuals and I’m sure many of you do as well. Searing bright computer screens, as it turns out, aren’t the best on your eyes and most of us would benefit from moving the brightness of our displays down a couple notches. That’s not to say there aren’t times when you need to crank it up: it’s just that on average we could probably all do without all the lux.

Auto-brightness isn’t something widely available on Chromebooks right now as an ongoing feature, but it also looks to be on the way. As it stands now, some Chromebooks will take an auto-brightness stance upon boot, but the first time you adjust it manually, that setting is gone and won’t return until you reboot. I’d rather have the option to simply turn it on or off in the settings tray similar to what I do on my phone: auto-brightness most of the time and a manual adjust when I need it.

I’d really like to see Google implement Adaptive Brightness across the board like we get in Android. It’s like auto-brightness with a little machine learning. I can manually adjust as needed, but it will still continue to re-adjust after I’ve stopped tinkering or doing what I was doing while I manually changed things. For me, it has been the absolute best auto-brightness I’ve ever used and I’d love to see it fully implemented on all Chromebooks with ambient light sensors. It is there on the Pixelbook Go, but only on boot. After I mess with the brightness, it backs off and stays away far too long for my liking.

Fortunately, it seems a simple auto-brightness is coming to ‘Hatch’ Chromebooks starting with the Galaxy Chromebook. As you can see in this commit, the files are being added for all the ‘Hatch’ Chromebooks and being tested on for ‘Kohaku’ at this point. We’ll eventually see all the ‘Hatch’-based devices that have an ambient light sensor get this, but it is clear that the Galaxy Chromebook could directly benefit from this ASAP.

With auto-brightness on, a battery-saving governor enabled, there’s a real chance the Galaxy Chromebook could get the battery situation under control. I don’t think this will result in massive gains and there’s basically no chance we see Samsung or Google get this device on that 12-hour battery level, but the improvement could get things more firmly in the 8-10 hour range when the display’s massive brightness isn’t being completely abused. If that is the case, this will solve the only real weak spot on this Chromebook and remove the unfortunate blemish that is already being attached to it.