How to tell if your smartphone's battery is healthy or bad (iPhone and Android guide)

How to tell if your smartphone's battery is healthy or bad (iPhone and Android guide)
A smartphone without a battery is like a time machine without a 1.21-gigawatt nuclear power source. In other words, it is useless – the battery is what provides that magic juice every smartphone needs to operate. 

Unfortunately, even if you take good care of your smartphone's battery, it will inevitably degrade over time and lose some of its charge capacity. At that point, it might be hard to tell if the cell is still in good health or in need of a replacement. That's why we thought we'd share a few tips on the matter.

Perform a visual inspection

You don't need to be a rocket scientist to tell a faulty battery from a healthy one. In fact, some common battery failures are easy to spot with a naked eye. If the battery of your phone is removable, simply take it out with caution (after turning the phone off, of course) and look for symptoms like bulging, corrosion near the metal terminals, and green or white-ish stains. These are all signs that the cell is about to kick the bucket. If you don't see anything wrong with it, proceed to the next tip. If you find suspicious stains or if your cell has developed a hump, however, it is a good idea to ask your carrier or vendor for advice as your battery most likely needs to be replaced. Don't put the old cell back inside the phone as you don't want it leaking any nasty chemicals; these may damage the phone's circuitry. Instead, seal the battery in a plastic zip bag and make sure you recycle it once it is confirmed to be faulty by a professional.

Do a spin test

Lithium-based batteries degrade with each discharge cycle. Not storing them properly makes matters even worse – extreme heat or cold may seriously shorten their lifespan. Another way to ruin a perfectly good battery is to drain it and leave it with no charge for a long time. Eventually, a battery might swell if not treated with care. This swelling happens slowly, usually over the course of weeks and even months, which is why a hump that has just started forming on the battery's side can be pretty hard to notice. To check if your battery cell is fine, try spinning it on a flat surface – if it spins, it might have gone bad. Obviously, this tip applies to user-removable batteries only.

Observe how fast your battery level drops

Not all phones have batteries that can be easily inspected by the user. If that's the case with your handset, you can diagnose the health of its cell by monitoring how fast its charge level drops. It is not supposed to drop by two or more percentage points at a time. (Most phones allow you to have their battery level displayed as a percentage in the status bar. If you can't find the option in its settings menu, try using a widget.) And if your battery goes from full to zero in a matter of hours even when you barely use your phone, its is probably a goner.

More battery diagnostics tips

iPhone users, here's something you might not know. Your iPhone keeps track of how many times its battery gets charged, and it also monitors the actual capacity of the cell inside it. However, this information is meant to be accessed only by Apple's support staff, hence you won't find it in your settings menu. Thankfully, there's a workaround. You just need to get iBackupBot – an all-in-one utility for managing iDevices, available on both Mac and PC (Download link). As soon as you connect your iPhone to a computer with iBackupBot running, the application will detect it and let you access detailed information about it. In iBackupBot, highlight your phone in the list of devices and choose "More Information". There you'll find your iPhone's charge cycle count, as well as the actual capacity of its battery. If the FullChargeCapacity figure is much lower than the one under DesignCapacity, then the battery may have to be replaced. (Keep in mind that a lithium-based battery usually loses about 20% of its capacity after 500 charge cycles.)

Android users, your phone also stores data about the health of its battery cell. To access it, try entering the code *#*#4636#*#* in your dialer –this should take you to a service menu where battery details are shown. If the code doesn't work, try Battery by MicroPinch (Download link). It is a simple battery monitoring tool where the health status of your battery is displayed, along with its voltage and temperature. 

More battery tips and tricks for iPhone and Android users



1. grivera96

Posts: 3; Member since: May 04, 2014

Thanks for the info. It works on my ipad (shows 12 cycles), but on my ipod touch it says 0. I have it since june 2014 and I would really like to know how many battery cycles it really has. Any alternatives for ios devices?

2. Neros

Posts: 1016; Member since: Dec 19, 2014

3rd pic code doesn't work on TW with android 4.4.2.

3. Fluffy3477

Posts: 4; Member since: Apr 05, 2014

the code does not work on my GS5 5.0

10. UglyFrank

Posts: 2200; Member since: Jan 23, 2014

Mine too

11. Calzone

Posts: 12; Member since: Feb 04, 2015

*#0228# works on almost any TW device.

16. defcon888

Posts: 39; Member since: Nov 03, 2014

worked....thanks....Samsung Note 3

7. Wiencon

Posts: 2278; Member since: Aug 06, 2014

Awesome article, thanks PA.

8. Sealblaighter

Posts: 435; Member since: Jan 26, 2014

"Lithium-based battery usually loses about 20% of it's capacity after 500 charge cycles." This is about Lithium Polimer batteries or about Li-Ion type too??

20. RandomUsername

Posts: 808; Member since: Oct 29, 2013

Lithium-Polymer is a type of Li-Ion battery.

21. Sealblaighter

Posts: 435; Member since: Jan 26, 2014

So this means every battery for mobile devices loses of it's capacity after 500 charge cycle right?

9. tttony

Posts: 29; Member since: Jul 22, 2012

Cool! Tested on Xperia P 4.1.2

13. kaikuheadhunterz

Posts: 1157; Member since: Jul 18, 2013

*1.21 jiga-watts

25. pegasso

Posts: 285; Member since: Nov 27, 2011

LOL! true! it was spelled "jiga-watts"

15. Sidewinder

Posts: 515; Member since: Jan 15, 2015

Times when a non user removable battery becomes a curse.

17. namesib

Posts: 97; Member since: Feb 08, 2015

"It will inevitably degrade over time and lose some of its charge capacity" Yep, or just not function properly (phone switching off suddenly then losing most of its reported charge after switching it on again). I do not want to send my phone to a service centre, which is why I have no intention of buying a device without a removable battery.

18. KidAndroid

Posts: 39; Member since: Nov 04, 2014

Well then I'd keep your phone you have now as more and more manufacturers stop using removable batteries your soon not going to be able to get a device with a removable battery. Even Samsung who is praised by many for their removable battery capability is said to be ending their removable batteries this year starting with the Galaxy S6. I'm with you though as I'm a huge fan of removable batteries but I'd buy devices with a non-removable battery and have many times, I just usually get rid of my devices when I get a new one so I've actually never had any battery issues with batteries sealed or removable.

19. livyatan

Posts: 867; Member since: Jun 19, 2013

This is why removable battery is a must for me. If Samsung drops that feature for their entire llineup, they will lose the last respect I hold for them.

22. Stuntman

Posts: 843; Member since: Aug 01, 2011

I had a battery bulge on me. Replaced it with a new one now.

23. GalaxyS5

Posts: 430; Member since: Aug 05, 2014

If a battery is draining quickly, while not showing humps and bumps on it, it's time to "calibrate" your battery if you're rooted, or to reset your smartphone if not rooted. dad used to have problems with the note 3 he had after a year of purchasing it. I rooted the smartphone, calibrated the battery and it worked like heaven. and so does reset worked for me before. but if the battery is dead just buy another one.

24. b3rno93

Posts: 1; Member since: Jan 06, 2015

Well, i didn't knew that, and its funny cuz I did it, and then I looked at the pic, and noticed that its the same Launcher, so you do use Zenfones, it must be the new one(a test model probably), but still, I just love that UI

26. harrigrassy

Posts: 1; Member since: Jan 06, 2016

Probably you didn't know that almost every battery, old or dead, can be reconditioned to be useful again! This can save you lot of money and it's also a way you can contribute to protect the environment :) Check this link to learn more about it!

27. Disha1

Posts: 1; Member since: Dec 14, 2017

all these points are very helpful But personally, check all my battery details within a single app named Full Battery Charge Alarm and Theft Security Alert which is available totally free for android Very helpful app

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