Reference the above post for a pretty accurate description of what my phone is doing. The difference is I had the SIM card problems long before the sudden power drain. I have done as suggested and put the phone in safe mode, uninstalled all apps that I could and uninstalled all updates to apps that I could not remove. I kept the phone in safe mode overnight. I was able to use the phone alright with FB (did not know that was now a standard app), and the battery was getting low as normal. It it just turned yellow and I restarted my phone to take it off safe mode. As soon as it came back up, I got the 9% power message and it went black. I had this happen two or three times yesterday when it was not in safe mode, and each time after it was fully charged. I noticed that every time, except once, I was in FB. The other time I was in Words with Friends, but had been on FB for a while before that.
The first time the phone went black on me and I restarted it, to find it had 8% power, I told my husband about it. He did a hard reset to see if that would help. It was ok for a day or two, then it started happening again. I noticed when he did that reset, my phone looked different, (has a Verizon "tab" next to the app tabs now). Since the reset, it is only worse. I was preparing to buy a new battery when I found the above message and his description was almost identical to what is going on with my phone, so I started thinking it is not the battery (though it is the one that came with the phone over 2 years ago). I can buy a new battery, but do not want to do so if it is not going to make a difference.
There is a strong possibility it is one of the apps that is automatically installed, but I cannot remove those. It could be the new operating system, I don't know. But I do not want to have to buy a new phone if I can help it, because it means I will have to go with a new plan, instead of my current one which has unlimited data and I only have to pay $9.99 for the two other phones on my plan (regular - not smart phones). I would appreciate any help. Thanks!
Oh, and something else. I am not getting all text messages that are sent to me (my husband replied to a couple that I did not get, but get others - he has shown me his sent messages and they appear to have gone through). Also, it appears I am not getting all my voice mail or even getting a ring when someone is calling me. I have been told by one person in particular that they called me and left a voicemail, and I never got that message or a missed call notification. I have no reason to question their truthfulness.