Lumia 950 battery drains rapidly

A couple of nights ago, something wonderful happened. I took the phone off the charger, and the battery drain issue was gone. While not in use, my 950 consumed around 2%/hour (which is fine), and 10-15% while running Edge (also fine). I had a great phone again, just like the other low-end Lumias that I have owned previously that only needed charging every other night, and this lasted for about a day. Then I was back at 5-10%/hour idle consumption and 15-20%/hour when in use. I was a wall-hugger again.

Since then, I have seen this pattern of alternating between acceptable and unacceptable numbers, without being able to pinpoint what triggers the transitions. It doesn't look like a hardware problem, but it's really difficult to tell. The only unusual thing that I did just before the phone got those fantastic power consumption numberswas to accept a Wi-Fi Sense prompt that wanted me to authorize Facebook. I hadn't seen this prompt on that phone before, and when accepting the access request, it looked to me like both the Facebook and the Settings apps crashed. It could be that something really did crash in the background too, causing a sharp drop in power consumption, or it was just a lucky coincidence, and the Win10 UX team is no longer even trying to implement transitions that don't leave you confused and scared.

I have also had this"remission" currently my 950XL is behaving beautifully. When it's good it will easily charge on my fat boy pillow overnight and remains cool. Doesn't seem to be many clues as to why it changes it's behaviour, but I suspect that charging the phone sometimes has something to do with it.

Another thing i have noticed that always triggers "good" behaviour is when I take the phone out of range for a while. When the phone has no mobile signal for an hour or so it hardly drains any battery and stays good for some time after I get back in range.

A couple of nights ago, something wonderful happened. I took the phone off the charger, and the battery drain issue was gone. While not in use, my 950 consumed around 2%/hour (which is fine), and 10-15% while running Edge (also fine). I had a great phone again, just like the other low-end Lumias that I have owned previously that only needed charging every other night, and this lasted for about a day. Then I was back at 5-10%/hour idle consumption and 15-20%/hour when in use. I was a wall-hugger again.

Since then, I have seen this pattern of alternating between acceptable and unacceptable numbers, without being able to pinpoint what triggers the transitions. It doesn't look like a hardware problem, but it's really difficult to tell. The only unusual thing that I did just before the phone got those fantastic power consumption numberswas to accept a Wi-Fi Sense prompt that wanted me to authorize Facebook. I hadn't seen this prompt on that phone before, and when accepting the access request, it looked to me like both the Facebook and the Settings apps crashed. It could be that something really did crash in the background too, causing a sharp drop in power consumption, or it was just a lucky coincidence, and the Win10 UX team is no longer even trying to implement transitions that don't leave you confused and scared.

This morning I send my 950 XL to repair, It's not possible to have a day with this phone, battery drain ...

I try to install the last inside os same thing

I try after reinitialised the phone, to desinstall all I can, turn all programs off in backward, turn wifi bluetooth, gps, off

always same thins : 28 % by hour !

I don't know if it's a hardware or os fault, but If MS can't find the way, I want money back !

I'm happy with the battery performance after the reset - I get about 15 - 17 hours before it goes in to battery saver, and that's with fairly constant "puttering" with some fairly crappy apps - Facebook and MSN News/Edge being the big hitters. Even an hour long Skype call over a two-bar cell connection didn't hurt it too badly, which was a surprise.

My numbers are very similar to yours - generally 22% system, 73% screen, 80+ % foreground apps. I think there may be an issue with the display driver for the 950 (at least I hope, so, given those numbers), as it is an OLED display and should be more efficient than an LCD. But my old 920 that I just upgraded to WM10 is flipped the other way on numbers: 75% system, 20% display. And it looks like it will go a couple of days in idle mode (it's just been sitting on my desk since I upgraded it yesterday).

One  thing I did do to the 950 last night is take the screen off of auto-brightness and dimmed it down (just to see if it has any effect on the numbers - auto seemed to keep it too bright, anyway).

I don't do a whole lot of uploads from the phone, but it's never seemed to be much of a problem. If I get a chance I'll try a few and see how long it takes for photos to arrive.

If I have understood the Cellular Data setting correctly, it means that the phone will fall back to cellular if the current WiFi connection has no route to the Internet (i.e. a bad hotspot of some sort) - something I was under the impression that WP8 already did. Thanks for pointing out that this is now a setting in W10, which was disabled for me.

Now, the bad news is that enabling this setting changed nothing, nor did enabling OneDrive to upload over cellular data connections. Uploads are still extremely slow, error prone, and consume battery (relevant to this thread). Back to USB it is.

Since you are now happy (?) with the battery life after the hard reset, has anything in the power usage distribution changed? For me, 60-70% of the power is consumed by the Display, followed by System at 25%. 80-90% consumption is foreground apps, with Edge being the top app with over 50% of the total. These numbers have been fairly stable for me - are they very different from yours?