What is your phone’s battery trying to tell you?

Jan 17, 2016, India

Around a year ago, my phone began routinely running out of charge by 3 pm because I was using it in a lot more ways. Battery intensive tasks like shooting a stage performance had become risky as the phone would be dead in an hour, or sometimes even less!

Before figuring out how to fix it, I needed to know what was going on. This post is a record of my attempt to understand what makes the battery tick, and how to keep it ticking. Please note that I’m no techie, and am just using simple logic to understand what the phone is telling me about itself.

The Facts

A phone’s battery life depends on its battery capacity, hardware, OS (operating system), and apps it runs. Logically, shutting down power-hungry hardware, or apps which use that hardware, should conserve battery.

But in reality, it doesn’t make sense. For instance, using Google Maps on a drive will drain my battery pretty fast as it uses two power hogs: the GPS chip, and the screen (in always-on mode). Turning off the app will save my power, but I won’t get directions to my destination. That defeats the purpose of having google maps, or for that matter, a smartphone.

Turning off is not on

Turning off phone features is easy. Remembering to turn them back on isn’t. I have often missed calls by turning off the ringer, and later forgetting to turn it back on. If this can happen with an in-my-face phone function, how likely am I to remember to turn back on a background function like GPS? My kid recently lost her iPod and if its GPS had not been turned on, and we might never have been able to track and find it.

Know your phone or get a better phone

So basically I have two choices. Either figure out how to optimise my phone to use less power. Or get a new phone with a bigger battery. I have tackled both ways in this post. (The new phone route is in the second half of this post). But I’m guessing you wouldn’t have started reading this article if you were not the type to be turned on by batteries!

One last thing. I’m not too familiar with Android but find its battery usage similar to my iPhone in many ways. Still there are quite a few differences , which I have addressed in the section succeeding the iPhone one below.

What my iPhone is saying

Cellphones today track battery usage, though Apple and Android do it in different ways. On iOS, you go into Settings>Battery. Seen below is battery settings from my iPhone. The one on the left is for last 24 hours, and the other is for the last 7 days. I clicked the clock icon on right hand top corner to get actual times. Let me see if I can tell what those apps are saying.


Whatsapp is the biggest power drain on my iPhone. Probably because it’s my default messaging app, that I also use for VOIP calls. The power seems to have been mainly consumed by the phone screen being on.


This runner-up power hog had only 5 mins of screen-on time over the week but background usage was 2.7 hours. I figured that the GPS chip which ran in the background, was the one eating its way through all that power.


Seriously power hungry app. I was shooting a slow motion video, and it was on for just 12 minutes but used 3% of battery.

Mi Fit

This is on all day and connects my phone to my Mi Band which counts my steps and vibrates when I get a call. It used just 2% over the week.


My music was on for 4.2 hours in the background (on my EarPods) but barely consumed 3% of the battery.


This app is on 24/7 and counts every one of my daily 10,000+ steps via my phone’s M7 processor, but does not even show up in battery usage.

Joker in the pack

I need to keep an eye on Veer, an app I was trying out. It’s a widget to make quick calls from the notification screen and used 2% yesterday, possibly because I was configuring it with the screen on.

Do’s and Don’ts

  1. Screen: I avoid using it continuously, as it’s a major power consumer. I noticed this even on my iPad, which has a massive 11,666 mAh battery but was down after about 5 hours of non-stop writing. So if I need the screen on, I plug in my phone, or switch to a desktop, if that’s available.
    Turning the screen brightness down also helps. The upcoming version of iOS 9.3 has a feature called Night Shift which cuts down blue light at night. If you can’t wait, try this hack to reduce screen brightness.
  2. GPS: I turn off apps that use GPS after I’m done with them. Like if I’m using Google Maps to navigate and realize that I have chanced upon a familiar road.
  3. Multitasking: I have stopped shutting down apps visible in the multitasking view. I don’t think they are really running in the background, but more like a list of recent apps. Runtastic for instance, appears in the multitasking view, but does not connect to the GPS once I click ‘Finish’ after an activity.
  4. Bluetooth: No need to worry about leaving it on. The Bluetooth LE (low energy) version seems to sip very little energy, and only used 2% over the week.
  5. Motion Sensor (M7): Good idea to leave this one on, as it barely uses battery while taking a lot of the load off the main processor.
  6. Phone: Avoid if I can. A 2 minute call took 1% of the battery. I usually try to message instead of calling wherever possible.
  7. Wi-Fi & 3G/4G: Battery hogs again. Surprisingly, I get zero battery usage during the 5–6 hours I’m asleep, when I turn off both these when I go to bed. I do leave the phone on, so I’m reachable in case of an emergency.
  8. Charging: The current theory is that if you let a battery drain completely before recharging it, it tends to shorten the life of the battery. I usually top up my battery whenever possible, and avoid it dropping below 30%
  9. Other ways to save battery are by turning off vibration, notifications, email push, background apps, location, or you can even leave on battery-saver mode permanently. But you can save a lot more battery by turning the phone completely off, if you get my point!
  10. Apple’s own battery recommendations include not exposing your device to temperatures over 35∘C, storing a phone with a half-charged battery if you don’t plan to use it for a while, and updating to the latest OS.

When I go to bed, I turn off all electromagnetic radiation emitters (wifi, data, bluetooth and even cordless phones/base stations) except the phone. I’m not sure if these invisible waves are interfering with my sleep/health, but I would rather be safe than sorry. See my post on that for more details.

What my Android is saying

My Mi has a modified version of Android (MiUI7) that gives a lot of battery info, though most of it is Greek to me. I went to Settings> Additional Settings> Battery and Performance>Battery use. You can see battery usage by hardware or apps, and even a history of use since phone was turned on.

I checked the battery usage over two days: Day 1 (above) being low use of phone and Day 2 (below) was medium use.


Since I didn’t use the phone much, Whatsapp was not the usual glutton it is.


I took the Mi on my morning jog and had the music app on for half an hour. Runtastic barely registered on the battery at 2%. That would be the blue square beside GPS in ‘History details.’ The music app didn’t show up.

Mi Store

I spent an hour onscreen with it, and the app showed 12% use. All signs on the history image point to the screen and wifi being the culprits.

Android System

Android differentiates between system usage and app usage, unlike Apple. I turned off all radios (data, wifi, bluetooth) before I went to bed but its battery was still down by 4% in the morning. The history image on the right shows the phone was kept awake though the night. I’m guessing the blame is on the email alert notification lights that were blinking all night.


I hadn’t used this app but it had 2% battery use. The funny thing was it only had permissions to read contacts. Deleted it. Problem solved.


My Mi has an option to speed up the phone by reclaiming memory. It does this by going to the multitasking view and either shutting down all running apps, or the ones I select from the list. This implies that quitting apps in multitasking on an Android stops unnecessary battery usage.


Unlike iOS, Android allows apps like Twilight to control blue light at night or even set screen brightness to whatever level I wish.


The latest Android OS seems to be taking a more effective and customisable route to battery use. You can see precisely what the app is doing and turn off functions that drain the battery. For instance, I clicked on Facebook, and then on App permissions to see what it was using. Quite a surprise too!

Battery usage on iOS vs Android

My iPhone has a larger screen and a smaller battery than my Android (2750 mAh vs 3100 mAh), but lasts longer on an identical workload. Apple’s iOS is probably more efficient than the Android in battery usage. Marshmallow however has better control on how apps use the battery, and features like Doze that stop apps from using the battery when the screen is off.

Epilogue — a new phone

As I was mulling over all this, the matter was abruptly taken out of my hands. My iPhone 5’s display unexpectedly went into a coma, and I was soon mournfully writing its obituary, but with mixed feelings. My pocket hurt, but my inner geek was feeling gleeful about a new gadget. One thing was clear. The battery would be a key factor in choosing a phone. So I explored options like the phone battery itself, battery cases, and battery packs.

The hardware combinations

  1. Medium sized phone with a large battery: My choice was the 5" Xiaomi Mi4i that comes with a 3120 mAh battery.
  2. Big phone with a big battery. The top one in my wishlist in this group would be the 5.5" iPhone 6S Plus with its 2750 mAh battery. It’s a bit too large to carry around but should last a day, unless used nonstop for hours on battery intensive functions like shooting photos/videos.
  3. XL battery. The 5.5" Lenovo Vibe P1 with a huge 5000 mAh battery
  4. Battery case. Apple has more or less admitted there’s an issue with the iPhone 6S by launching a battery case for it. Sadly, it led to ‘ugly’ being associated Apple for the first time. Battery cases are more convenient than battery packs but don’t add much battery life for the extra weight.
  5. Battery Packs. The pros for battery packs are they charge fast if they have a 2A output, and need to be attached only when you need power. The cons are carrying a phone, battery pack and cable can be a bit too much. My choice here was the Xiaomi 10400 mAh Power bank.

The Winner

I ended up buying the Xiaomi Mi4i after deciding to switch to Android (you can read about my switch in detail here). In a nutshell, the Mi4i’s size was just right, and its price made it possible to consider upgrading every alternate year. I felt the other phones were a bit too big. I do have a Sony 5000 mAh battery pack as a backup for when I travel, but generally don’t carry it around as it’s extra deadweight in my pocket.

Twist in the Tale

A month after I bought the Mi, my wife called me from the Apple Store to say she was picking up an iPhone 6S for me. She finds it hard to get me gifts as I am a person of few wants. But she knew I’d been using Apple for ages, and figured she could finally gift me something I really wanted. I tried telling her I didn’t need another phone, and an expensive one at that. But when I saw I couldn’t convince her, I asked her to get the 6S Plus for its larger battery. Now all I need is an extra pocket to carry my second phone!

That’s it. I pulling the plug on this post.

it’s an odd world

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