[Thunderbolt General] OdinGuru:
High Level Symptoms:

- I notice battery has drained very quickly in a short time even when I have not been using phone (i.e. idle with display off)

- Phone feels noticeably warm/hot even when I have not been using phone (e.g. like it does while charging)

- Issue only seems to happen when running in 4G LTE mode

- I have gathered detailed usage statistics and do not believe there are any miss-behaving apps or system processes responsible

- I have noticed issue start most often near my office (in midtown NYC)

Note: This is where I use the phone on battery the most, so it may just be sampling bias

- I can temporarily stop the rapid power burn by switching out of 4G LTE mode (i.e. to 3G mode, or disabling radio)

- I have not found a way to stop the issue in 4G LTE mode once it starts except by restarting phone

(things I tried without success: toggling airplane mode, switching to 3G and back to 4G, radio off/on, and moving to different location/tower; rapid burn starts back up again as soon as 4G LTE mode is re-enabled)

Power Burn Rate:

- Data captured using Battery Monitor Widget which I have set to sample/log battery available % and usage every minute (this is a great app!)

- Available % dropping at a rate of about 20% / hour while phone is idle w/ screen off (my normal is about 5% / hour)

- Usage shows a very flat baseline of about 1000 mW / 250 mA (normal baseline is more like 100 mW / 40 mA)

(by baseline I mean many samples are equal to that baseline value with the rest being spikes up to greater values; no observed values are less than the baseline)

Background Info:

- My phone is unrooted and running stock firmware w/ the Verizon OTA upgrade (installed ~2011-05-19)

- I have noticed this issue many times since first getting the phone (~2011-04-12), and this issue is still present even with the newest LTE radio FW in the OTA update

- I am new to Android (~2 months in) but I am diving in deep with all the amazing tools both built-in and via add-on apps; I have collected a range of data/observations from numerous sources that are detailed in this post

My hypothesis is that the LTE radio hardware is responsible for this power burn. Most likely due to a software/firmware bug, but I'm not sure how to confirm that.

I wonder how common this issue is. I remember reading other posts on the forum that sound like the same thing. For example: http://xdaforums.com/showthread.php?t=1008761

Can anyone else confirm they have seen this issue? If this issue is wide spread, I think it may be a contributing factor to the wide spread reports of 4G LTE a lot of battery.

I do not think this is the only factor that causes 4G LTE to use more power than 3G. I have read the reports, and personaly seen, higher 4G LTE power consumption when in low signal areas. However, I belive that to be independant from the burn issue I am describing here. The worst case power consumption I've seen that I think was "low LTE signal" related was only about 500 mW / 130 mA. The burn issue I'm refering too consumes power at about twice that rate and happened when I had strong signal. I had three to four of four possible bars. Also, I grabbed more detailed information:

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Phone info

reached using "LTE OnOff" app, "Network" app, or by dialing *#*#4636#*#* -> Phone information

Signal strength: -67 dBm to -80 dBm, 3 to 4 asu

Location: BID = 39b SID = 16 NID = 4

LAT = 7fffffff LONG = 7fffffff

Network Type: CDMA + LTE/EvDo auto

I believe this is good signal (e.g. issue not due to a low signal condition)

==================

Usage Data Capture

I briefly connected to power to reset the statistics after noticing the issue had started and and captured about an hours worth of data. My understanding of the data is that the display was off for almost all the time, and no apps or system processes are listed as using any significant amount of CPU/sensors in comparison to the hour data collection window.

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Battery Use

reached using Settings -> About Phone -> Battery Use, or Battery Monitor Widget -> Usage

When last unplugged for 57m 12s

Display 30%

* Time on 1m 11s

* Auto Brightness

Cell Standby 21%

* Time on 57m 12s

Phone idle 19%

* Time on 56m 1s

Foursquare 11%

* CPU total 8s

* CPU foreground 6s

* GPS 26s

* Data sent 13.59 KB

* Data received 379.93 KB

Android System 7%

* CPU total 41s

* CPU foreground 2s

* Data sent 12.09 KB

* Data received 20.27 KB

Android OS 6%

* CPU total 39s

* Data sent 20.11 KB

* Data received 136.25 KB

Pandora 6%

* CPU total 35s

* Data sent 1.83 KB

* Data received 27.16 KB

---------------

Battery History

reached using Battery Monitor Widget -> Statistics, or by dialing *#*#4636#*#* -> Battery history

since last unplugged

CPU usage

* Android System (Total time:39s)

* Pandora (Total time:35s)

* suspend (Total time:31s)

* Foursquare (Total time:7s)

... (Note: more apps listed but with smaller total times)

Sensor usage

* Android System 29m 47s

* AccuWeather.com 28m 36s

(Note: after this capture I uninstalled AccuWeather.com app and retested. It wasn't listed anymore, but power drain behavior was unaltered)

Partial wake usage

* K-9 Mail 7m14s

* Android System 5m 4s

* Seesmic 9s

... (Note: more apps listed but with smaller times)

Other Usage

* Running (27.6%)

* Screen on (2.1%)

-------------------

CPU Spy v0.3.0 beta

Note: timers reset at begining of measurement interval

Time in state

1024 MHz 4:21 7%

768 MHz 0:54 1%

368 MHz 0:35 0%

245 MHz 12:11 20%

Deep Sleep 41:34 69%

This is a typical distribution I see when the phone is mostly idle (CPU sleeping for most of the time).

=================

Variation testing

After the data capture I systematicly tried several methods to see what it took to stop the abnormal drain in 4G LTE mode. In the end only rebooting the phone did it.

Set preferred network type: "CDMA auto (PRL)" (i.e. 3G mode) -> normal power usage (5:00pm-5:18pm)

Set preferred network type: "CDMA + LTE/EvDo auto" (i.e. 4G mode) -> abnormally high power usage (5:18pm to 5:43pm)

Set airplane mode (i.e. radio off) -> very low power usage (5:43pm to 6:54pm)

Turned off airplane mode (i.e. 4G mode) -> abnormally high power usage

Set preferred network type: "LTE mode" (i.e. ONLY 4G mode) -> abnormally high power usage

Set preferred network type: "CDMA + LTE/EvDo auto" (i.e. 4G mode) -> abnormally high power usage

Moved to a new place:

Signal strength: -65 dBm 4 asu

Location: BID = 23c SID = 16 NID = 4

LAT = 7fffffff LONG = 7fffffff

-> abnormally high power usage

Phone info "Turn off radio" button -> very low power usage

Phone info "Turn on radio" button -> abnormally high power usage

Restart phone -> normal power usage