Phone crashes and battery drops below 10%

Device info:
Brand: Samsung Galaxy S2
Model: GT-I9100
CyanogenMod version: 12.1-20150905-NIGHTLY-i9100
Android version: 5.1.1

So I've noticed that whenever my device seems to crash and I have to hold the power button to turn it off. When I turn it back on the phone states that my battery is low and that I should plug in my charger.

I'll use my most recent crash as an example, so I was watching a YouTube video it got to about halfway through before it stopped. Now I first thought that the other half of the video hadn't loaded yet, so I tapped the screen and got no response.

I tried the home button and the back button (of course with a delay before pressing the other), but still nothing happened. So I held down the power button to turn the device off (despite the phone being frozen that's the only button that works), I turned the phone back on and surprise surprise my phone has 1% in battery left.

Now I don't know if this is because my apps are by default installing to the internal storage and I have to manually move them to the SD card or if the phone needs a new battery.

I'm updating to the latest version to see if it runs any better.

Posted via the Android Central App

So I updated to CM version: 12.1-20150912-NIGHTLY-i9100

So not long after my phone updated its fps dropped to 10 (I don't have an actual clue how far it dropped, this is just an example number) and then slowly dropped to zero, to where I had to turn the phone off and then back on.

After I've backed up the games on my phone, I'll uninstall all the games on my phone and see if this changes anything.

Posted via the Android Central App

Hi there, I would pursue a new battery as one for that model is pretty cheap on Amazon or other outlets. Reading your description makes me thing the battery itself may be going bad. Either way, if it's not the battery you have a good spare. When you get the new battery, if the behavior persists, I would do a clean flash of the device after backing up data. If the issues STILL persist, I would roll back to an earlier nightly.

OK, after uninstalling the 24 games I had on the phone (keep in mind that i had to manually move them to the SD card) I haven't seen it crash once. But I'll see if I can get a new battery for the phone and report back if it continues.

Posted via the Android Central App

Hmmm, interesting. I am not a huge fan of moving apps to SD, but I understand that space is an issue with the device. Let me know if you have other issues.

Did you tried to change the battey? Try that :)

Sadly, i haven't been able to find a battery that fits my phone. I looked in a few places, but they only seemed to have batteries for completely different models. All of the batteries i saw looked nothing like the battery in my phone, i will keep looking.

Search your specific model on Amazon is my recommendation. I find a lot of good replacements there.

Amazon was one of the first places i tried, but it doesn't show any batteries for my phone. And yes i did make the search specifically for my phone and that still turns up batteries that won't work for the phone.

This search on amazon took me 3 seconds. Here is a battery. https://www.amazon.com/Anker-1900mAh...cUvbUpU4749530

This won't work?

How many pages did you have to go through to get that? I went through at least 10 pages and didn't see that amongst the results. From what I can see I think that battery might fit in the spot.

Where the battery currently sits in:
Attachment 201662

Current battery:
Attachment 201659
Attachment 201660
Attachment 201661

Battery you found:
Attachment 201656
Attachment 201657
Attachment 201658

Posted via the Android Central App

It literally was the first result for me.