Phone is turning off at 70%, and after booting it up again it says 1%. Still, recovery works

[Android Central Question]

Hello.
I have an Xperi Z3. I use a custom AOSP ROM.
When it is booted, it cannot go lower in percentage than around 70%, because it turns off (with showing the Turning Off screen). When I boot into the recovery it shows me that it is at 62 percent and I can use the TWRP for another hour or so before shutting the phone off itself. I wiped ART and cache, made a full charge cycle by draining the phone with consant turnon trials and charged it to 100% while it was turned off. The problem still remains. What can I do? Also, I think the problem was also present on stock system, before I flashed the AOSP a month ago.

Now recovery says 53% and the phone just shuts off, like the battery is unplugged from it, if I boot into the system.

What can I do? I don't think that it is the battery (mainly) causing it.

 

[Mooncatt]

I don't think that it is the battery (mainly) causing it.

Why do you think it's not just the battery? That would be my first guess. The only thing throwing me on that, though, is you said it'll do a proper shutdown at 70%. This may be a quirk of that phone, able to tell when it's about to die. But the fact that you said it will sometimes shut off as if you pulled the battery makes me think it's due for replacement anyway. So I'd start there and see if that fixes the initial problem too.

 

[Norbert Magyarics]

Hello, I'm the OP.

The reason I think it is not a battery problem is that I can be doing anything in TWRP for hours before the phone turns itself off completely.

So if it first reaches the percent it will shut down at first, it shuts down normally, but the second time it's just battery pulled feeling. Yet I can stil use recovery for hours from then on.

That is strange, because TWRP also runs on battery and works like charm.

 

[themadscientist]

Of coarse I havnt flashed on a HTC in a long time but sounds like if not battery a kernel problem or such I would flash all stock to see of it still happens

 

[themadscientist]

If it does happen stock. It more than likely is a battery issue. As in twrp different things are happening. Than when device is booted

 

[Mooncatt]

Hello, I'm the OP.

The reason I think it is not a battery problem is that I can be doing anything in TWRP for hours before the phone turns itself off completely.

So if it first reaches the percent it will shut down at first, it shuts down normally, but the second time it's just battery pulled feeling. Yet I can stil use recovery for hours from then on.

That is strange, because TWRP also runs on battery and works like charm.

Hello and welcome to the forums. As @themadscientist pointed out, TWRP isn't doing as much as full on Android, which will make a difference with a weak battery.

Any time you put a demand on the battery, you'll see a temporary drop in voltage (aka "voltage sag"). This is normal and to be expected. If you've ever had your AC kick on and watched the lights in your house dim a bit, you're witnessing voltage sag. The amount of demand placed on the electrical system (the battery, in our case) determines the amount the voltage drops. The bigger the demand, the bigger the drop.

If you're gaming, that'll place a huge demand on the battery. On a healthy battery, the voltage sag is minimal. As the battery wears out, the sag becomes worse and can dip below the cutoff point before the phone realizes it, which causes a shutdown. Using TWRP is putting very little demand on the phone, so the sag is almost nonexistent. That is why you can use it longer before it shuts down. Think of it like running vs walking. If you try to Sprint, you'll tire quickly and need a rest. If you walk, you could go much longer before needing a break, and travel further than you did sprinting.

As a side note if you do replace the battery, try to keep it in a happy medium. It's bad to drain a Li-ion battery to zero and also to charge it completely. If you plan to keep it long term and want the battery to last as long as possible, the general guideline is to try keeping the battery between 40-80%.

 

[Rukbat]

Sounds more to me like a dendrite (a temporary short) in the battery. The dendrite drains some of the battery so, at 70%, it shorts the battery enough to drain it to 62%, at which point the battery voltage drops low enough to shut the phone down - for an instant. Once the phone has started going into shutdown, the dendrite has burned off, so instead of just going blck (as it would if the battery were fully shorted), it continues a normal shutdown.

When you turn it back on, in TWRP, it continues to work, because the dendrite occurs at 70%, so you have no further problem.

The solution to a dendrite is a new battery - we still don't have dendrite-free batteries. (See Lithium Battery Dendrite links for more information and the latest news on dendrites.)