[Android Central Question]

A while back, my phone started to shut down when it hits 70% battery level. When it started happening, it was running Android 6.0.1, but since then it was updated to version 7.1.2, but the problem still happens. I've read online that I should discharge the battery all the way to 0% and then charge it to 100% (full charge cycle), but I can't do this, because the battery doesn't go below 70%.
Thanks for your help

[Mooncatt]

A while back, my phone started to shut down when it hits 70% battery level. When it started happening, it was running Android 6.0.1, but since then it was updated to version 7.1.2, but the problem still happens. I've read online that I should discharge the battery all the way to 0% and then charge it to 100% (full charge cycle), but I can't do this, because the battery doesn't go below 70%.
Thanks for your help

When this happens, are you able to turn it back on, or do you have to plug it in to charge first?

When you do finally get it back on, what is the battery level? For example, shuts off at 70%, but turns on at 10%.

Does it get hot when this happens?

It may be that the battery is bad. One of the symptoms of a bad battery is an immediate power off (meaning it doesn't go through the full shutdown process) before reaching zero, but I will say doing so at 70% is the most extreme case I've seen.

If you create an account so you can reply, it would help us better address your issue by answering those questions. It will also help if you let us know which phone you have and how old it is.

[anon(10408467)]

Thanks you for replying.

Regarding your questions:
- Yes, I can turn it on after it shuts down, but it shuts down after I insert my PIN. The battery level is at 1%. If I plug the charger, it shows 70% and continues charging up to 100%.
- As far as I can tell, the phone doesn't seem hot.
- Before shutting down, it shows the 'Powering off' screen.

PS: My phone is a BQ Aquaris M5 and it is 2 years old.

[Mooncatt]

I was all set to say the battery is bad, until I saw this.

- Before shutting down, it shows the 'Powering off' screen.

I guess it's possible a phone could do this with a bad battery, but I know mine will just die as if I pulled the battery. No shutdown screen, just instant off.

How old is the phone? How low did you normally let the battery go before charging (before this problem started, of course)?

I'm still leaning towards the battery being bad. If you want to dig a little deeper, can you install this app?

https://play.google.com/store/apps/details?id=ccc71.bmw

It's a monitoring app. In the options, set it to record the history every minute or so. Then charge the phone and use as normal until it shuts off. When that happens and you get it running again, go to the graphs and switch to the voltage graph and take a screen shot to post here. If you see wild swings where it dips low and comes back up, then it's most certainly time to replace it.

[anon(10408467)]

Here is the screenshot:


The 23% and 55% happened after the phone randomly restarted. After that, I plug it in, and it went back to 73%.

The phone is 2 years old and before this started happening I let it go all the way to about 10-15%.

[Mooncatt]

You do have some large swings in there. Anytime you put a load on the battery, it has a voltage sag. That's normal and to be expected, but usually isn't very noticeable on a healthy battery. As they age, the voltage sag becomes worse, to the point of no longer being able to run a device despite having a higher resting voltage. That's what is happening with yours and why it shuts the phone down.

Letting it drop to 10-15% is likely what caused it (Li-ion batteries should not be discharged below about 40% for longevity). So your best bet is to replace the battery. If you want the best life from it, try to keep it between 40-75%. Yes, this means charging it more frequently if that's your goal. Fully charging it isn't as bad as a deep discharge, but can still impact overall longevity.

[anon(10408467)]

Thanks for all your help, Mooncatt.

I will follow your advice of keeping the battery level between 40-75% and get a new battery.

[Jun Banez]

Can any one help also me, as i have the same problem my phone suddenly shutting off and it will not turn it back unless i need to plug in the charger and battery percent are still the same the when shutting off.

[belodion]

^ A bad battery, perhaps.

[KnightRider242]

I have a phone which powers off at 75%..If i use it while charging (eg like playing PUBG) it automatically drains out completely and i remove my cable it switches off...idk wat 2 do

[B. Diddy]

Welcome to Android Central! Which phone do you have? It sounds like the battery is failing. If the battery is user-removable, try a new battery. If not, then bring it to a repair shop for battery replacement.

[stackberry369]

My LG V20 is doing this as well

[B. Diddy]

Does it also happen in Safe Mode?

[Nick Hoover1979 Wride]

Today my Galaxy S4 just shut down with 91% battery. after immediately restarting it the battery suddenly dropped to 13%. the phone was not hot either. I am concerned because if it is a bad battery recharging it could mean fire or explosion.

[Mooncatt]

Today my Galaxy S4 just shut down with 91% battery. after immediately restarting it the battery suddenly dropped to 13%. the phone was not hot either. I am concerned because if it is a bad battery recharging it could mean fire or explosion.

A bad battery doesn't mean it's a danger to use. Most out these are just lost capacity but can otherwise be used as normal. If your battery is removable, take it out and see if it looks deformed. If it's puffed up, that is something to be concerned with. If it looks flat, try spinning it on a flat, smooth surface on both front and back of the battery. If it spins a while before stopping, it's still puffed up, just not much. There's still a risk with continued use in this case. What we hope to see when you spin it is for the battery to stop almost immediately.