Discovered cause of Battery Drain lumia 920/820

Question

Hi,
I just registered to tell you following:
I discovered the culprit that is responsible for the "semi random" battery drain.
@Home my Lumia 820 "shines" with a good battery life.
@Work:
- without any additional Installed app
- no active background task (except standard entries: "extras+info" and Nokia Music)
- every (backround)sync disabled (mail, also xbox, music.....)
- display low
- disabled location service
- closing all apps with multiple clicks on back-button
- uninstalled skype
- disabled apps @ lockscreen
- battery saver on
- backup disabled
- nfc disabled
- microsoft account sync only 1x per day
- disabled roaming (my provider is a roaming monster :-) roams into networks of other providers).
- 2x fully discharged + fully charged + 12 hours on powersupply
- and every other suggested energysave option/action i could find on internet and here in forum -> except hardreset
With all above mentioned methods the battery still gets/got literally eaten away at work in IDLE.
I had it next to me with monitor off. Only checked once per hour and it died in ~8-11 hours. No call no message no nothing.
I was curious why it only happens at work: The difference of the network coverage is, that at home it is far more inferior. I have to search for a spot in my house where i can use it for calling somebody.
So Internet is not even an option (also no HSPA+ coverage throughout the village). Normally you would have less battery life at places with less connectivity. But not in that case.
I investigated further: on the way to work I use it for surfing ~50min - 1hour -> there i loose 7-9% of my battery. (very good result for driving with car => many connection losses)
As soon as I reach the city where the Lumia reaches the HSPA+ network it begins to drain veery fast.
HSPA+ needs much more power than UMTS and I guess normal HSPA!
I compared the behaviour with the Samsung Galaxy S3 (colleague's phone) and noticed a small but profound difference:
After you "wake" the S3 from idle it will show on the screen, that it uses UMTS and not HSPA/HSPA+... as soon as you start surfing or start an app that connects to the internet the S3 switches immediately to HSPA+. After a little time the Samsung switches back to UMTS.
The lumia behaves differently: It detects HSPA+ and uses it. Also in idle!?
I followed this obvious lead and wanted to disable HSPA/HSPA+ -> unfortunately it only lets you disable 3g as a whole (UMTS/HSPA) so I switched to 2G only.
While I am writing this my L820 is unplugged 6hours now and
after much heavier use than normal (mailing, surfing with 3g while driving 45min home [which dropped the charging-level multiple times faster than gaming!], 1h gaming, 10 minutes calling)
the remaining battery life is at 70% with estimated time remaining: 1day 7hours left (after writing the whole story it went up to 2days 4hours with 69%... but i guess thats because its idleing).
This behaviour is also the explanation why some people are affected and some aren't.
Summary of change: from initially 8hours idle and not even touching the phone -> to finally using it now with 70% after 6hours with 1day 7hours time remaining.
Additional info: I live in Austria (Europe; no kangaroos ;-)) --> so I have a Lumia 820 with the german firmware without the update, which was released in USA and Canada:
Revision: 1232.2109.1242.1001
So please implement a similar function like the Samsung S3 ... or just as a start: let us manually turn off UMTS, HSPA and HSPA+ separately! Surfing with 2g is no fun.
Sorry for the extensive and long story/facts ;-)
Regards
V4mp

Answer 1

I can confirm that my battery drain problem is related to LTE  on my US Lumia 920, at home where signal is weak I get fantastic battery life, less than 2% drain an hour, lasts for well over a day with moderate usage. My work however is located in an LTE zone and as soon as I enter this area battery life becomes catastrophically bad, several times the phone has died on me before my shift even ends. Something like 15% drain per hour, sometimes worse., I pick up my phone and even though it has been completely idle for hours it is a bit warm to the touch. I have no idea what it is doing when it is just sitting there.
Trust me, I have tried all the tips from all the other users, none have worked. This is not a problem with background applications or some feature being switched on, I have tested this phone running bare bones no apps or a fully day on "battery saver" mode which seems to make no difference, the problem persists. The only way I can make it through the workday is if I put my phone into Airplane Mode, the drain then completely stops, again at less than 2% an hour.
I am amazingly frustrated by all this, my Lumia 900 never had this problem with LTE, I almost never gave the battery a second thought with my 900, but with the 920 I am constantly worried about being stuck with a dead phone, I have almost no apps installed on the phone because I am afraid of any additional drain on the battery. I have to put my phone in Airplane Mode if I plan on spending more than an hour in the civilized world, I am so unhappy with my experience and I really miss my Lumia 900. I really wish Nokia would acknowledge that this a problem with some 920 handsets, and it is a problem, we are all not suffering from some sort of mass delusion. I have spent weeks troubleshooting and trying to find the cause. I really don't know what to do at this point.