Black and white: does Samsung’s monochrome mode save battery life?

When Samsung rolled out its Galaxy S5, the surprise wasn’t the camera or the screen or even all the fitness tech. No, it was the ultra power saving mode, and how you could cut the colours to save on battery life, but is this tech really helping you save?

Battery life is becoming one of those features that’s hard to guarantee.

We all want better battery life that pushes on past a day, while still delivering a big screen, media playback, and a whole bunch of other nicknacks too, such as heart rate monitoring, wireless audio, compatibility for smart watches, and great cameras.

The catch of including all of this technology is that it can really dent the battery, cutting the expectations of days of life into something that’s closer to reaching a single day, if you’re lucky.

Ask owners of the iPhone 5 and 5S how much battery life they get out of their phones, and many will tell you of the problem of needing to charge daily. Unfortunately, Samsung’s Galaxy S5 caters to this expectation as well, barely lasting a day in our own tests, with power users requiring a charge nightly.

But one of the more unusual features included in Samsung’s Galaxy S5 was one included to save power.

Instead of just pulling back on the performance of the handset — which is basically what most power saving options do — Samsung has made the decision to shift to a lighter version of Android that only lets you run some critical apps (such as the phone), pulling back on the overall performance, and even dropping the amount of colours on screen, the latter of which brings the whole thing back to the days when things were in black and white.

It’s an interesting concept, that’s for sure, and it got us thinking: if Samsung believes monochrome can make a dent on the battery life when in ultra power saving mode, will it improve the battery life when monochrome mode is switched on all the time?

In theory, a super AMOLED screen could provide better battery life in monochrome mode because black OLED pixels may not require as much light since they are their own light source. With black being the darkest a pixel can be before it’s switched off, the theory stems from there being less colours, and therefore less bright pixels consuming power.

With that in mind, people have tried all sorts of things to improve battery life of phones to take advantage of this concept in the past, such as using black wallpaper, monochromatic themes, and less scaling across colour spectrums, such as what Microsoft tries to do with its Windows Phone operating system and the block colours on black or white screens.

But Samsung’s idea for a monochromatic mode takes the idea to a new level, with the possibility of cutting all colours out of the picture if you don’t need them, a sacrifice that could deliver a better battery.

That’s the idea in theory, and if a form of colour blindness affects you, the idea might be one worth taking advantage of simply because you don’t need all the colours. Indeed, anyone with achromatopsia or another form of colour blindness might want to switch this mode on to help them get the most amount of battery power without needing any of those pesky colours that they can’t see anyway.

So we tried it one weekend, which is now possible after Samsung made a minor update to the Galaxy S5.

Before it, monochrome mode was only available if you switched the ultra power saving mode on, but now with the update, anyone can use their phone without as many colours. Rather, you have grey, and lots of it.

With monochrome mode switched on — the only part of the ultra power saving mode that was active — we spent our time walking around town and spending a day using the handset the way we normally would, surfing the web, making phone calls, doing the whole social networking thing, taking photos, and generally using the phone.

And while it performed spot on just like the Galaxy S5 we reviewed recently, the problem was that it performed pretty much exactly like the S5 we reviewed, battery and all.

So does the monochrome mode help the battery life on the Galaxy S5?

Short answer: No.

Slightly longer answer: No, not really.

Long answer: Yes, provided you’ve switched on the ultra power saving mode, which doesn’t just cut the screen colours, but also pulls back on the amount of processes you can run simultaneously.

In fact, the ultra power saving mode isn’t just a process cutter, as it changes the launcher and only lets you run a few different apps.

With this in mind, the shift to monochrome makes sense, because Samsung is trying to get you to use the phone less, and reducing colours will surely help with this, as it makes things like web surfing, image editing, and Instagramming just a little less colourful.

But the change in display options isn’t really boosting your battery life. Not by much, anyway, especially in comparison to all the other things Samsung is switching off, like the connection options and concurrently running applications.

Interestingly, the phone still captures screenshots and camera pictures in full colour, so while it might seem like the phone is operating in monochrome only, the display is working in greyscale, with everything else working in tact.

But the battery life? That’s close to being the same, so if you decide to change to the colourless mode, realise that you’re not going to get much battery life in exchange for less colours.

Our screenshots might show up in colour, but our device was in monochrome, and the battery life wasn't so different between the two modes.


  1. This was not a scientific test. “we spent our time walking around town and spending a day using the handset the way we normally would.” You said it yourself that in theory it should work. So lets test it properly.
    I have an idea for an experiment. Get two brand new phones that are exactly the same. Set the screens on both to never turn off. Turn on monochrome on one and keep the other one normal. Fully charge their batteries and boot them at the same time. Time how long it takes for each phone to die. After you’ve done this, repeat the experiement with the batteries swapped to account for variations in the two batteries. Determine the proportions and test for significance.

  2. According to displaying process:
    1. CPU/GPU writes image/graphics to RAM
    2. Video engine (image enhancing, blending) reads/modifies content
    3. LCD controller reads out for displaying
    If the image is b/w, the bandwidth is reduced 4 times (32-bit ARGB -> 8-bit grayscale per pixel ), thus power is cut down 4 times due to shorter access cycle, and processing time.
    Basically, using monochrome with fully hardware (IP in SoC) configuration is feasible. However, if software is used for this feature, then nothing changes ! Hope Samsung doesn’t trick user !

  3. It’s not that I think they’re wrong per se, but rather that our testing suggests it’s more a gimmick than an actual battery saving thing across the board.

    Ultra power saving mode is more than just pulling the colours out of the screen, as it switches off quite a few synchronisations and wireless settings, so while this mode might save life, monochrome by itself doesn’t appear to.

  4. So in the end, even AMOLED can’t thwart E-ink’s throne in term of battery life. We need more the likes of Yotaphone, if only they makes it more worldwide available.

      1. It’s more about target market really. Battery life has always been an ugly stain on smartphone’s profile, better visual has been paid with less operation time. I know many peoples has to use two phones, one smartphone for more modern needs, and one feature phone as the reliable backup for their basic needs. A smartphone use E-ink display would be the best of both world, large display to read news or map, better battery life, excellence display while outdoor. Add in some rubber case and I can see many who work on sites or roads would loves it.
        Of course only if they willing to trade the vibrant of a standard LCD to the life of black and white, that’s would be a big hurdle indeed. At time like these, i wishs the development of color E-ink display didn’t get canned so soon, its a shame.

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