Battery Issues/Replacement Batteries

[cnashx]

So, since having some issues with my Elite X3 I have been using my 950XL for the last few days. This phone was purchased in November of 2015 so it's not "new". One thing I have noticed (it has happened twice) is although the battery life says 30-40% the phone shuts off and won't turn back on until it's charging, Then when rebooted the battery life is at 3-5%.
I am assuming this is because the battery is on it's last leg.
I have been looking online for batteries and have found some "genuine" and some others. Just wondering if anyone has had experience with some of these batteries and if anyone has had the same issue as me with the instant drain?

If you have purchased any of these batteries, any recommendations?

Thank you.

 

[andrew-in-woking]

I just bought one of the genuine Microsoft ones. I have had no problems with it so far.

 

[cnashx]

I just bought one of the genuine Microsoft ones. I have had no problems with it so far.

Where did you get it from?
The "genuine" ones from Amazon are questionable without sufficient reviews.

 

[NYCMetsPDX]

I purchased one from rounded.com based on recommendations from others as well as one off of eBay from seller z_xinhua. Both appear to be genuine based on inspection and serial numbers on the batteries (Note, I had to sift through tons of pictures on eBay to find a picture with a serial number and even then I was skeptical...).

I also bought another off eBay before I knew what to look for. If you see the words LCG_BV_T4D_PhoneProgram_v6.0 where the serial number should be I'd stay away, I bought and used one of those before I knew what to look for and the phone shut off and wouldn't turn on even with a soft reset (as I could do when the original battery died).