Database Users

[REF] Leo power consumption breakdown

With the HD2's pretty short battery life compared to my previous HTC phones, and also as I was a bit bored , I decided to have a look at how much the different systems drain in the HD2, and did some tests.
So for anyone interested, here are the results:
Base consumptions: (pick the one that suits your situation)
Standby, phone on, WIFI+BT off, no connections active: 5mA
Processor running idle, screen off, connections as above: 55mA
100% CPU usage (Coreplayer benchmark), connections as above: 315mA
USB connected, connections as above: 125mA
Additions: (add this to the base one depending on what you have on)
Connections:
BT on, idle: +1mA
Wifi on, idle: +5mA BUT!! If you enable wifi during standby (with BsB Tweaks or the WifiNoStandby CAB), the processor does NOT go to standby
anymore, so the base needs to be the 55mA above!
Connected to EDGE, idle: not measureable
Connected to 3G, idle: +4mA
Beware those 2 will occasionally and unpredictably send data every now and then, so this doesn't necessarily mean much.
BT transfer (file copy through ActiveSync, 120kB/s, CPU usage ~2%): +80mA
Wifi transfer (file copy with Wifi Remote access, 1MB/s, CPU usage ~3%): +200mA
EDGE/3G transfer: Pretty impossible to measure due to so many variables, but can be extreme (total current consumptions of 850-1150mA, so very approximative 500-800mA draw from the data connection during page loads are common!), and leads to most of the energy draw when using the net a lot. EDGE uses more power than 3G, consumption is higher when network coverage is lower, bad network throughput or congestion also mean lots of retries/overhead and less effective data transfer, using power for a longer time until the data is finally there.
Memory access (large file transfer):
Internal read/write through ActiveSync (speeds 2.5 / 2.1 MB/s respectively): +20mA / +130mA
Card read/write through ActiveSync (speeds 3.2 / 2.7MB/s respectively): +25mA / +40mA
Card read/write in USB disk mode (speeds 7.5 / 5MB/s respectively): +40mA / +45mA
Backlight:
10%: +65mA
20%: +78mA
30%: +90mA
40%: +105mA
50%: +121mA
60%: +136mA
70%: +154mA
80%: +170mA
90%: +190mA
100%:+210mA
GPS:
+95mA
Flashlight (with HTC Flashlight):
Level 1: +32mA
Level 2 (same as camera flash on): +107mA
Level 3 (same as camera "bright flash during shot"): +530mA
And remember the battery capacity: 1230mAh
So with this you can calculate your battery life for various activities. For example:
- Playing a video with full backlight: Let's say the video is well encoded (30% CPU use, for example 720x400 1Mbps DivX), that's about 150mA base, + 210mA backlight = 360mA, resulting in about 3h20 battery life.
- Same at night with only 40% backlight: Life goes up to about 5h!
- Wifi during standby for an 8h night, or a program that somehow prevents the phone from entering standby: 60mA or 55mA respectively, draining about 40% of the battery during that time.
- GPS program, with 70% backlight: Let's assume 150mA for the processor as it has some work to do, 90mA for the GPS, 154mA for the backlight = 394mA, or 3 hours.
- Music through wired headphones, screen off: the 55mA base plus a little 5mA as MP3 decoding is nothing for the CPU = 60mA or 20h.
- Same with a BT headset, with about half the BT bandwidth: 60+40 = 100mA or 12h
etc.
Charging
[EDIT 14.04.10]
This is now a dedicated section as I did some more thorough charging tests.
So, as some of you might know, the HD2 has 2 charging "modes".
- One is USB, that is used if the phone is connected to a PC, or an unknown device. In this mode, the current the HD2 will draw from the port/charger is limited to approx. 470mA, to stay within the maximum of 500mA a USB port can supply.
- The other is "dedicated charger", which is recognised on the original HTC charger (and some others, it's becoming a standard for a "dedicated charging USB port") by shorting of the 2 data pins of the USB connector in the charger.
USB charge
Important to know, during USB charge, the phone will NOT go to sleep, as it's supposed to be connected to a PC, and be running either ActiveSync, Disk drive mode, or modem, and in all 3 cases would be expected not to shutdown. So not only the current supplied to the HD2 is low, but the phone draws some of it for itself, leaving very little for actual charge - so expect loooong charge times.
USB charge with screen on (backlight dimmed, 10%): 285mA
USB charge with screen off (standby): 345mA (which shows the processor still runs and draws the "base USB" current)
Dedicated charger
When used with a charger that has the 2 USB data pins shorted, such as the original charger, the HD2 will draw a current that is proportional to the voltage on the USB power lines. To measure this I have used the original supplied USB cable, a variable regulated power supply, USB socket (with data pins shorted), and 2 meters for voltage/current. Voltages are measured at the "PC" end of the USB cable, so not taking account of losses in the USB cable. Will talk more about this later on.
Current vs Voltage diagrams are attached. Charge current is proportional to voltage, linearly until it reaches the max charge current, approx 830mA. This was measured so that the only draw is charge. If the phone is turned on while at max charge current, it will draw extra, until it reaches about 980mA, and will then stop to respect the 1A rating of the stock charger.
Now, to the influence of USB cables. I initially had some trouble with inconsistant numbers, phone only drawing 670mA from the stock charger, i.e matching neither the ~350mA from USB, or ~830mA from stock charger in "normal" condition. Turns out that to make it more convenient on my workplace I was using an USB extension between charger and HD2 cable. It was a $2 extension I bought on Dealextreme. Removing it solved the problem... and after making those measurements I poked with it again. Turns out that at 1A current, the voltage drop in the extension (which by the way isn't longer than the HD2's USB cable) was 1.8V! Yep, nearly 2 Ohms for a 1.5m extension! Couldn't believe it.
I have a cheap Chinese microUSB cable that wasn't as bad,but still significantly more resistive than the stock one, hence me noting I used the stock cable for my tests. So, quality of the cables, extensions, adapters IS important! Note the phone correctly reaches full charge current a little bit under the 5V USB spec, so everything is well tuned.
Now, important to know, Most 3rd party chargers will not have the 2 USB data pins shorted, and will thus result in the same behavior as mentioned under USB charge, the processor will also be running continuously drawing the "base USB" current.
It is often possible to modify 3rd party chargers by opening them and shorting the pins, speeding up charge. The voltage/current curve behavior is actually helping there, because thanks to it if the charger is overloaded its voltage will most likely fall a bit, and the HD2 will thus draw less and find a nice balance point. This DOES NOT mean there's no possiblilty of damaging the charger, but all 3 I modified did well. One that was really weak resulted in not much more current being drawn after the mod than before (i.e voltage fell very low, approx. 4.4V), however the gain from not having the processor running like in USB mode still sped up charge a little.

Thank you, that is one useful chunk of comprehensive information
Could you please explain the exact measuring method for these tests?
40% backlight at night is a tough example tho, Lumos on my device is set to 10% for 0 sensor value, and only because I can't set it to lower than 10%... nice to know battery drain goes up twice from 10% to 60%!
Also, 100% is usually really necessary under direct sunlight, in a normal lit room probably 40% backlight is more than enough to watch a video... all in all, with your superinteresting info, the battery doesn't look like lasting "too short" now, but more or less "the right amount considering the battery capacity".
My iPaq 210 has a 2200mAh battery, just to make a comparison... that's why I could go for 8 hrs during some bus trips while watching tv series, and I just needed to swap battery and used a little of the second one.

What's your estimate of the drain caused by activating push email? I've recently been doing some rather crude experiments myself, and one provisional conclusion is that push email on a hotmail account uses a lot more battery than push email on an Exchange server.

Excellent stuff, you are to be congratulated.
I have a long held theory and I wonder if you are in a position to to test it?
I believe that battery consumption is greatly increased when an app is run from mem card and would be intrigued to see a comparison between an install to this as opposed to phone mem.
Any chance?

Battery levels
I found that power consumption of the battery got even worse after I went to Rom 1.66.707.1. However, after a few days, I let it run all the way out, switched back on, it ran out after a few minutes. Then after an overnight charge I found the battery (on standby) only went down by about 10 -12 % in 24hrs. I'm hoping this performance will continue.

What did you use for the testing?

pa49 said:
Excellent stuff, you are to be congratulated.
I have a long held theory and I wonder if you are in a position to to test it?
I believe that battery consumption is greatly increased when an app is run from mem card and would be intrigued to see a comparison between an install to this as opposed to phone mem.
Any chance?
Click to expand...
Click to collapse
That would be reasonable as reading from an external media will need energy to access its contents... still, once the app files have been loaded into the device's RAM, it shouldn't matter much
You could also test by comparing:
1) copy say 30mb from one location to another of the internal mem
2) copy from microsd to microsd
3) copy from mem to microsd
4) copy from microsd to mem

ephestione said:
Could you please explain the exact measuring method for these tests?
Click to expand...
Click to collapse
Simply using the built-in current sensor, getting the reads from AEBPlus battery information screen, and methodically turning things on/off once the others are evaluated and can be subtracted from the total reading.
ephestione said:
40% backlight at night is a tough example tho, Lumos on my device is set to 10% for 0 sensor value, and only because I can't set it to lower than 10%...
Click to expand...
Click to collapse
Really? You should force the backlight off then
I love bright images myself, so even in my bed in total darkness if I watch a video or photos I'll force 100% backlight I have Lumos set to force 100% for Coreplayer, Resco Photo manager and HTC album
Of course not for browsing or just messing around, in that case it's 20% for me
Shasarak said:
What's your estimate of the drain caused by activating push email? I've recently been doing some rather crude experiments myself, and one provisional conclusion is that push email on a hotmail account uses a lot more battery than push email on an Exchange server.
Click to expand...
Click to collapse
That's one thing I'd have no idea about... I've never used push email at all. And that's "standby usage", so hard to evaluate, as you never know when it kicks in.
Measuring that would need to be done on a long time. I'd say to leave your phone one night with push email off, one night with Exchange only, and one night with hotmail only, and then check the difference, preferably with a battery at about 80% charge at the start (mine seems to fall from 100% to 90% in a few minutes before becoming more regular, so I'd say the top of the scale isn't that reliable).
And I should really try push email once, that would be nice, but I *think* I have no provider that can do it for me... well I have a gmail account I never use, I should try to see if I can have it check my usual 3 mail accounts, aggregate and push... never really looked into that stuff.
pa49 said:
Excellent stuff, you are to be congratulated.
I have a long held theory and I wonder if you are in a position to to test it?
I believe that battery consumption is greatly increased when an app is run from mem card and would be intrigued to see a comparison between an install to this as opposed to phone mem.
Any chance?
Click to expand...
Click to collapse
Thanks
Well I'd tend to refute that theory, because when I tested the BT and Wifi in use I tried read from internal memory, write to internal, read from card and write to card, and all 4 were identical. I should have mentioned it indeed, but I was mostly interested to seeing if reads (wifi/BT "sending") and writes (wifi/BT "receiving") would have an influence on consumption, which wasn't the case, as well as whether the throughput was different, which wasn't the case either.
But I've done a few more tests, see the updated first post
One intersting thing is firstly that when the HD2 is connected to USB, the current draw grows significantly, so I've made a new "base consumption".
Next, the card is actually faster than the internal memory both in reads and in writes, tested both through activesync for consistency. Writing to the internal memory eats a LOT more than writing to the card. Reading from the card eats a little more than reading from internal memory, probably evens out as the reads are shorter due to faster transfer rate.
I've added some charging tests as well. Apparently, even if the phone "disconnects" from USB when turned off, the processor still runs and uses about the "USB connected" base current.

kilrah said:
Simply using the built-in current sensor, getting the reads from AEBPlus battery information screen, and methodically turning things on/off once the others are evaluated and can be subtracted from the total reading.
Click to expand...
Click to collapse
d'oh aebplus has a battery information screen, checking it right away In that case you'd have to take into consideration aebplus' current absorption anyway... which is not measurable as you cannot check the current intake of aebplus without aebplus being running
I have the cab on the sd already, but didn't install if after noticing that didn't work for button assignments with later versions of the rom... does it work for you on that side? I used the program all the time on my previous ipaq because it was oh so useful but never got around to notice it had a battery info subsection.
Really? You should force the backlight off then
Click to expand...
Click to collapse
Wouldn't have much sense doing it in the dark would it (admitting it's possible altogether on the HD2!)
But I actually used my oooold casio cassiopeia, about 7 years ago, with backlight turned off, while reading ebooks with speed reader plus during train trips, as the neon lights created a reflection good enough on the display so that I didn't need backlight...
in the end, the backlight died altogether and until I bought a new device, I managed to use it with light turned off

A flashing LED (incoming SMS warning, e.g.) seems to add consumption of 1-3mA.
Running FlexMail in background with a push service (IMAP IDLE) adds up to 30mA.

ephestione said:
does it work for you on that side?
Click to expand...
Click to collapse
AEBPlus works fine for me yes... but I don't have a "latest version" ROM AFAIK. I don't like WM6.5.x new softkey arrangement, so I'm staying with 6.5.
Anyway more about Push, I configured that through gmail yesterday, and it works just fine. I left it on during the night, and this morning I had lost 8% battery. So it's pretty much negligible. I received 2 e-mails during the night and was on 3G network.

this is a nice topic! i am interested in how much extra it uses when you are playing a MP3 with the build in HTC app?
maybe it would be a nice idea to make a program that outputs results like you pasted fast and easy (something like a benchmark app) so we can test different rom's fast? too bad i cant write anything otherwise i would try..

OK, seems MP3 uses 120mA screen off, both with Sense player and Coreplayer, so:
Processor running idle, screen off base + 65mA
But it seems to make some pretty big "jumps" once in a while. Maybe they both decode ior fetch from memory by "batches"...

my test,
HD2 rom 1.66
with BT on and BT off (configured but no connection to headset) difference in consumption is 60mA .!
BT is draining my HD2 .!
kilrah said:
OK, seems MP3 uses 120mA screen off, both with Sense player and Coreplayer, so:
Processor running idle, screen off base + 65mA
But it seems to make some pretty big "jumps" once in a while. Maybe they both decode ior fetch from memory by "batches"...
Click to expand...
Click to collapse

OK, I can't confirm the BT issue. Did you observe over a long period of time? The "quiet" current for MP3 I seem to get is 185mA with screen on and backlight at 10%, but sometimes it will climb to 280-320mA for a moment and go down again, both with BT on and off. With screen off for a while it seems to stabilise at the "quiet" level.
BTW, it seems that Advanced task manager isn't reporting CPU usage levels properly. Does someone know of a CPU monitor that works correclty on the HD2?

Yup. review over multiple 6 mins. all baseline(3g/brightness) setting the same. resetting each time for off on BT.
kilrah said:
OK, I can't confirm the BT issue. Did you observe over a long period of time? The "quiet" current for MP3 I seem to get is 185mA with screen on and backlight at 10%, but sometimes it will climb to 280-320mA for a moment and go down again, both with BT on and off. With screen off for a while it seems to stabilise at the "quiet" level.
BTW, it seems that Advanced task manager isn't reporting CPU usage levels properly. Does someone know of a CPU monitor that works correclty on the HD2?
Click to expand...
Click to collapse

Another consideration:
Data connection sucks power when used actively. Badly. As mentioned in the OP I haven't made comprehensive tests due to low monthly allowance, but I've had a look during normal use.
I'm pretty regularly doing 1hr train rides, during which I will be listnening to music , and browse the net at the same time. It's usually bright, so backlight will probably be at 70%. Signal is relatively low most of the time, on EDGE, inbetween small towns. When I'm on a "static" page (reading an already loaded page), current drain varies between 250 and 350mA.
But while loading a page, it will easily soar to 800mA+. Considering it takes 30-60 seconds to read a page, 20 to load a new one, and repeat... you can quickly see that this kind of usage leads to serious drain... in less than 2 hours the battery would be dead.
So be aware of how much power data connection will use. It's directly proportional to the amount of transferred data, and the worse the reception the more power it uses.
I should try using opera mini again, like I was always doing on my Kaiser. I never noticed excessive drain with it, but opera mini easily divides traffic by a factor of 10...

Just wanted to report that the new version of the superuseful BattClock has now a builtin battery current output, even if it's not really update once per second... seems more like one every 10 seconds.
I get ~240mA playing fullscreen stretched Frasier in lowest backlight (but that's with the keypad leds turned on all the time, I don't know why they don't go off, and I don't have keypadledcontrol installed... so that's a problem), and I get a total 630mA with HTC flashlight at maximum.

Good news! Bye bye Batti
Normal about the refresh time, the sensor only updates every 20 secs or so.
Some new considerations I posted somewhere else but should have put here.
After some time the HD2 seems to have better battery life, but usually it's not your battery lasting longer, it's just you not spending your day playing with the thing anymore.
It's always the same thing, the more a device can do, the more you do with it. On my first 1h train journeys after getting my HD2, I was able to kill 50% battery in 1hr. My first thought was "wow, with my Kaiser I would only use like 15%!!"
But then I took a second thought. I used 50%, but I was browsing the web, in bad reception areas, while listening to music the whole time. With my Kaiser, I'd put music on, check 3 webpages, then put it on the tray with just MSN connected and just pick it up to read/type a message once in a while.
On a next trip, I "forced myself" to do the same with the HD2. Just checked the news for 5 mins, then only listened to music and picked up msn once in a while, plus an unexpected 10min phone call. Guess what? I've only used 20% battery during the trip this time
The "problem" is that browsing with the Kaiser was just painful, so I'd just check the news and put it away. On the HD2 it's so comfortable I forget it and just spend my whole trip browsing heavy pages, which obviously kills battery in no time...

exactly my thoughts and findings

Display Brightness problem with my Galaxy S

Display Brightness problem with my Galaxy S
Hi I have bit of a problem with my galaxy S' display. The display uses a ton of power (90% +, going down 1% every 2-3 minutes with display on) as per the OS usage data. I have not experienced brightness settings / power saving mode as having any effect in terms of extending my battery life.
Now here's why I think there might be something wrong with my phone. I know two other people that also have a Galaxy S. We come together often last time I noticed their displays are MUCH MUCH brighter. I took all three phones on the table and noticed that regardless of the brightness level I set on all three phones, whether it be the minimum brightness setting or full brightness (all 3 phones SAME settings of course) mine is always the darkest. Also their phones display 40-60 % from the total power used by their display's rather than mine always showing 90%+.
I tried a battery recalibration etc this doesn't do anything in my view. After trying some great suggestion on this forum, I alway set the display to its lowest brightness setting, still no difference.
One of those other phones is running the same S/W as mine (doc's rom JPA) the other is still on JM2, so I can definitely exclude the firmware version as a cause.
Any thoughts suggestions as to how to solve this? Or might I just as well stop bother with that and have Samsung exchange the phone's display?

I have the same problem.. Did you find a solution?

nikiiv said:
I have the same problem.. Did you find a solution?
Click to expand...
Click to collapse
Hi, No unfortunately I didn't. It is kinda strange I'm not getting any response on this thread. If you and I are having the same issue, I find it hard to believe we'd be the only ones!

There is a "smart management" option under settings (saves battery). This seems to change contrast etc when enabled and makes screen dimmer. I have to SGSs and I can confirm that, Check it and tell me whether it worked.
nb: this option will make a full white screen dimmer than if you have half white and half black (the white will be brighter in the second case - probably to improve contrast).

Hmm.. this is what I did.. I placed the brightness slider to the left and switched on the automatic brightness control. Now battery use does not show 50% or more in average use, but seems normal, like it was before froyo
Smart Management is off

HD2 WP7 Battery issues

Okie dokie, ive had a wee look about and whilst there are several posts on battery issues i dont see much on this one ive come across.
Ok, first things first, battery usage seemed a bit high but nothing too major, still got me through a day, then it got worse, bit by bit it was lasting less and less time. so ive done a few wee tests with flashing other WM roms and WP7 and i think i have a good explination.
It seems if you leave it on charge all night it may not quite fill up, if you unplug it when the green light comes on then plug it back in it fills up propperly, if however you unplug it when the green light is on and isnt full, plug it back in again and then unplug it again before its full it reports on wp7 as being full, which it isnt, then it looks like your battery is draining like a comet falling out of the sky which of course it isnt, just just your battery isnt full to start with.
anyhow, it seems to get worse if you dont notice it not filling up, so if i fill it up to say 80%, then use it, and at some point during the day plug it in briefly but not enough to fill it up fully it then takes that level as the battery max, the next recharge doesnt fill it up until a restart.
So yes, thats all rather complicated and probably makes little sence to anyone but me but the point is this, for one reason or another WP will think the battery is full when it isnt, which makes it look like the battery usage is massive, which it isnt, it just appears that way because as far as WP is concerned, under the right circumstances your battery is perhaps half the size it really is

I'd support dazza9075 in his articulation of this undocumented 'feature'. Without having given it the same levels of consideration, I've had similar experiences where I have had a phone on the green light - I unplug it, take a short call, plug it back in and it stays on amber for another hour or more.
Elsewhere in similar threads there was a suggestion to soft reset at bedtime. I haven't done so rigorously, but the once or twice I have done, it does seem that there is more battery left in the morning.
Of course, in the absence of hard data from a battery percentage meter - assuming it is accurate - this is all subjective speculation anyway. But it is reasonably safe to say that WP7's battery reporting is immature at best.

Aye, not having propper access to battery stats is a bit of an oversight. Just to add to my ramblings just charged the phone, green light, unplug, icon suggests 100%, plug in an amber light pops on, unplug an Icon dropped to around 80%, plug in again and leave phone on standby it will charge, but as I type on here battery icon gone straight to full an green light on.
Lesson of the day, charge and don't use phone, keep repeating unplug an charge to get full charge back

Good stuff guys! Indeed; i noticed the same thing! Although when it says Low Battery i can assure you that the phone will still work for a day like mine.. i charged it yesterday morning; at night it said battery low and still now i am using it! Weird stuff but as we know WP7 is not meant to be on HD2! Someone here (member or dev) will fix the problem some day like Android OS... This is just the Beginning!

I can completely agree with the observations written above regarding the battery charging in our HD2s.
Just install the Battery Tool from the HTC test package found here:
http://forum.xda-developers.com/showthread.php?t=896104&highlight=test
Then when you open the program, for fully (I mean really full battery) there must be the following lines there:
Code:
Weight: 1000
RARC: 1000
Voltage: 4196 (+/-, different, this is mine battery)
Current: 0
Full: 1230
ACR: 1230
Last one (ACR) and Weight (1000) are the most important, so that ACR == FULL. After that I can use the phone for 2 and half days with moderate usage.
When the usually charging appear, after the green light, when I open the application it says:
Code:
Weight: 686
RARC: 686
Voltage: 4196 (???)
Current: 30 (it appears still charging with small amount of amperage)
Full: 1230
ACR: 840
For me here the battery is 2/3 full, but is strange that it reports full voltage, although ACR << FULL. If I unplug the charger, then just right after some minutes I'm starting to see how the battery indicator decreases fast.
EDIT: It seems that after green light, If I unplug the charger and plug it again, the above settings change dramatically, as well as indicator, showing 2/3 full battery:
Code:
MS_Percent: 69
PA_Percent: 69
Weight: 686
RARC: 686
Voltage: 4196
Current: 75
Full: 1230
ACR: 845
Then after 2-3 minutes it's becoming green again and MS and PA pointing to 100, BUT Weight and RARC = 686.
The question is, is really battery 2/3 full or is just wrong determination of charging percents (battery indicator levels) as noted above?

ah, very good tool
I think that just proves what i suspected, the phone dosnt have a clue what its doing, to get a full charge, simply unplug when green light comes on, keep screen off on standby and replug-in,red light appears until it thinks its "full" repeat process until ACR is full. A reboot will have the same effect it seems
Failer to do so makes phone results in incorrect battery stats and can result in the phone appearing to have a much hight battery usage then it really does

hd2 wp7 battery tips
I struggled a lot initially then I did the following changes which made my battery last for 3 days, yes you heard it right.
1. Remove all live & Facebook (active) tiles from the home screen
2. Turn data/WiFi off when not in use.

yes, use the battery tool from htc to read and charge your battery to 100%...though it says 100%...charge until ACR reading and FULL reading are same or the battery current says zero....similar to current widget in android where the phone can be charged till the current is 0ma..meaning no current is passing between the phone and charger

Where do we get the battery tool from htc?
Edit: Foud the link in the above posts .... Thanx

Not exactly related but I have the same problem with charging, if I plug into my laptop it starts orange and turns green when its 100% but what it looks like to me is that when it thinks its charged it turns off the charger and the light still stays green.
So my battery starts draining but still showing green, if I unplug and plug back it will go to 100% but the same happens again.
Getting annoyed with this I got one of these...
http://cgi.ebay.co.uk/UK-USB-Desktop-Battery-Charger-HTC-HD2-LEO-T8585-UK-/260757456468?pt=UK_MobilePhones_MobilePhoneAccessories_MobilePhoneChargers&hash=item3cb65b0654
Its tedious taking my battery out but now I get over a full day without having to charge.
P.S. the battery tool is in this thread http://forum.xda-developers.com/showthread.php?t=911309

I'm a huge fan of this particular little battery-related nugget. And I'll be a monkey's uncle: it works.
http://forum.xda-developers.com/showthread.php?t=1041912
My personal habits call for a soft-reset at bedtime (while it's plugged in) and a little video camera shoot when I wake. This yields about 18 hours of battery life for me with constant 3G and/or WiFi usage. I average ~12,000 texts per month.

GameDr04 said:
I'm a huge fan of this particular little battery-related nugget. And I'll be a monkey's uncle: it works.
http://forum.xda-developers.com/showthread.php?t=1041912
My personal habits call for a soft-reset at bedtime (while it's plugged in) and a little video camera shoot when I wake. This yields about 18 hours of battery life for me with constant 3G and/or WiFi usage. I average ~12,000 texts per month.
Click to expand...
Click to collapse
which version of WP7 and radio rom are u using ? Presume its a EU HD2

[GUIDE] Tips on Awesome Battery Life for Power Users

Most of my droid using colleagues are quite impressed at how i manage to squeeze so much battery life out of my handset. I thought it was time to compile and share my tips and tricks with the community. I get about 20+ hours with relatively heavy use
First some caveats.
This is what I personally do - and I simply want to share if some of these tips and tricks can be useful for others. Your personal mileage will vary and not all of these tips will be applicable to all users. With that in mind, these are my personal requirements and phone capabilities which affect my strategy for longer battery life:
Some sort of data Connection Always On
At least 2,000 in quadrant after standard boot
Background Data Always On and AutoSync always on
WaveSecure and LBE Security Service Always On
Google Voice for sms and call forwarding/routing
1000 minutes + 5gb data grandfathered plan - so no use for major data monitoring and no use for wifi calling
Frequent use of bluetooth stereo headphones in conjunction with Amazon MP3 and Google Music Beta - music synced then listened to, rarely streamed
Infrequent use of Pandora
Required ROMS, Apps and Programs
Cyanogen Mod 7 Latest Nightly (kernel of your preference)
Tasker
Autostarts
Root Explorer
Titanium Backup (useful, not required)
Step 1: Remove CM Bloat
Before and after flashing a nightly I run Titanium Backup and backup all system apps just in case something gets ****ed up during what I do next. In general, I uninstall any apps i don't use and backup + uninstall any apps i use very infrequently.
I then uninstall the following:
File Manager (replaced by root explorer which is far more powerful)
Sound Recorder (keep in mind, im using GV for SMS and do not use MMS),
Music (replaced by the new google music from market and amazon mp3)
Voice Dialer (i've never understood the need for this when we have google voice search)
Home Screen Tips
Magic Smoke Wallpaper (if you don't use it)
Music Visualization Wallpapers (if you don't use it)
ADW Launcher (if you don't use it)
Gan Optimizer and Wifi Calling
Email (i only use gmail app and have it setup such that other accounts are forwarded, labeled, and gmail can SEND AS: other account)
FM Radio (people still listen to FM after howard stern went to satellite?)
Dev Tools (I never find a need for this)
Keep in mind all of these are backed up in case you decide you want them back or something breaks. Also, you might need to force close out of kineto/wifi calling before the uninstall through applications -> running services.
Step 2: Settings
I don't **** around with Render Effect for battery savings - it only helps on AMOLED screens (confirmed by c00ller here http://forum.xda-developers.com/showpost.php?p=14509485&postcount=4)
I have auto brightness disabled and use the status bar swipe brightness to adjust
CPU Governor: I prefer Smartass if available, if not then interactive, if not then on demand. I used to use Pershoot - but I think i now prefer Umaro or stock.
CPU Clock: I have this set to 1.2mhz. Honestly, its faster than most phones out there both in how it feels and quadrant score. 1.5 seems like overkill - and it will drain the battery faster. This really comes to personal preference though. Min should always be lowest frequency.
to make the system feel faster, i make all animations fast in spare parts. as a result, i do not use the screen on/off animations.
VM heap @ 32 mb
lock home in memory, use jit, enable surface dithering
GPS Always On
Step 3: Take control over startup
This where autostarts comes into play. Note that both After Startup and Connectivity Changed are triggered on boot - so this is where things need to be disabled. Here is what i have disabled:
xda premium
(Amazon) Appstore
Messaging (I only kept messaging so i can recieve t-mobile alerts)
Springpad
Maps (should be disabled unless you are a big latitude user)
Amazon MP3
Skype (keep enabled if you do sync and want to be signed in on boot)
Ebay (keep enabled if you have auction alerts on)
Touch Pal Dialer (still deciding if i like this or stock)
SyncMyPix
ROM Manager Premium License
DropBox
Netflix
Shopper
Firefox Beta (keeping this app around to see if it ever improves vs stock or dolphin)
(Google) Earth
(Google) Docs
Note that this isnt fully comprehensive for what u would want to disable - in general keep the google apps enabled and any apps u know should run at startup (for example those that receive push messages) or that you want to poll immediately.
Step 4: Automate with Tasker
I use tasker to do some automatic toggling of settings.
Primary battery savings: location based profiles that use location w/o tears (network location) that intelligently turn wifi on and off in locations where I know I have wifi access (for example in my apartment or near work + during work hours + not holiday + weekday). Under wifi settings -> advanced make sure the wifi sleep policy is set to Never.
I don't do this, but you may also want a profile that sets wifi off or data off or autosync off while at home during sleeping hours.
Secondary battery savings: when bluetooth is turned on, wait for connection for 3 minutes. if no connection is made, turn off. when bluetooth device is disconnected, check for another existing connection or new connection for next 3 minutes. if no connection is made, turn off.
Tertiary battery savings: Profile that alerts when battery is fully charged (with british higher pitched female voice) to prevent overcharging/battery damage (please correct me if this is a myth but ive found it to be true, anecdotally).
Additional Thoughts about Other Profile Apps and Tasker
I have found that apps like setcpu have a definite negative affect on battery life. Most kernel governors manage themselves properly and profiles are not needed unless doing heavy overclocking where you need high temperature failsafes.
Additionally, apps like juice defender seems to waste a lot of battery in their monitoring (versus Tasker) and I think the tendency for that app to toggle the cellular radio on and off (with that 20s delay) actually hurts battery. Again, I own these apps and have used them extensively and decided against them - but it does come down to personal preference. Still, an app like Tasker can do everything juice defender and setcpu do, if necessary albeit less intuitively, but with a smaller memory footprint.
A note on Bump Charging
See here: http://forum.xda-developers.com/showthread.php?t=871051
condensed: bump charging works but can weaken your battery in the long run. avoid it if you care about your battery longevity or have frequent access to chargers throughout the day.
Thanks to c00ler for the tip to byrong's research.
Open Questions that I have
Radio questions
If in a high 4g/3g penetration area - is it better to be on WCDMA Preferred or WCDMA Only?
If in constant wifi coverage - is it better to be on 2g only or a WCDMA setting?
If in constant wifi coverage - is it better to have cell radio off and make calls over wifi only?
Other questions
Is there any battery life correlation to USB PC charging vs Wall charging? What about stock charger vs other micro usb chargers?
Is battery weakened from extended time spent plugged in?
Is there anything else I am missing? I hope this guide is helpful.

Reserved for followup.

Great posts.
I recommend to freeze those system apps rather than to remove/uninstall them using Titanium Backup.
Considering that you 're using CM 7 nightly, there's a bit much work to do to uninstall the unnecessary system apps after flashing new ROMs.
Just don't know whether freezing a app would do more harm to performance than to just remove/uninstall them or not.

A few answers:
sundar2012 said:
Is battery weakened from extended time spent plugged in?
Click to expand...
Click to collapse
I do not know the exact answer but I will tell you that PC USB ports are limited to providing a typical maximum current of 500 mA while the wall charger that came with our device is capable of 1.0 A or 1000 mA. I use an app called Battery Monitor Widget and realistically I've seen numbers like 200-300 and 500-700 mA, respectively, as the charge current is a function of battery %. What I'm saying is USB charging for Wall charging is really more a matter of how battery life is affected by charge rate. I've read on the one had moving ions too quickly in a battery can lead to decreased lifetime while on the other, fast charging avoids crystallization of battery microstructure, which is good. Read more at batteryuniversity.com
sundar2012 said:
Is battery weakened from extended time spent plugged in?
Click to expand...
Click to collapse
Read this post.
sundar2012 said:
Does render effect only confer battery savings to AMOLED screens?
Click to expand...
Click to collapse
Yes, it only affects AMOLED screens. Why? Because in an AMOLED, every pixel IS its own light source. Every pixel can turn itself on and off at will. Therefore, darker wallpapers, images, themes, etc will have more pixels at a low-power state and lead to decreased power consumption. On the other hand, LCDs have a backlight that is always on, even when looking at a "pure black" image. To produce the dark image, the LCDs have liquid crystals that polarize the light perpendicularly to each other so that (theoretically) none goes through. However there is always leakage, which is why blacks never look as black as they do on AMOLEDs (lower contrast ratio), which can literally turn off to produce true blacks. Basically for dark images, AMOLEDs are dynamic go into a lower power state while LCDs are static and maintain one relatively high power state at all times.

c00ller said:
A few answers:
I do not know the exact answer but I will tell you that PC USB ports are limited to providing a typical maximum current of 500 mA while the wall charger that came with our device is capable of 1.0 A or 1000 mA. I use an app called Battery Monitor Widget and realistically I've seen numbers like 200-300 and 500-700 mA, respectively, as the charge current is a function of battery %. What I'm saying is USB charging for Wall charging is really more a matter of how battery life is affected by charge rate. I've read on the one had moving ions too quickly in a battery can lead to decreased lifetime while on the other, fast charging avoids crystallization of battery microstructure, which is good. Read more at batteryuniversity.com
Read this post.
Yes, it only affects AMOLED screens. Why? Because in an AMOLED, every pixel IS its own light source. Every pixel can turn itself on and off at will. Therefore, darker wallpapers, images, themes, etc will have more pixels at a low-power state and lead to decreased power consumption. On the other hand, LCDs have a backlight that is always on, even when looking at a "pure black" image. To produce the dark image, the LCDs have liquid crystals that polarize the light perpendicularly to each other so that (theoretically) none goes through. However there is always leakage, which is why blacks never look as black as they do on AMOLEDs (lower contrast ratio), which can literally turn off to produce true blacks. Basically for dark images, AMOLEDs are dynamic go into a lower power state while LCDs are static and maintain one relatively high power state at all times.
Click to expand...
Click to collapse
Thanks, will update thread to reflect information about bump charging and AMOLED.

Discharging the battery ?

Question ? Setting - Battery - Display I still have about 80% load even after turning on the power, just whenever there look. I performed a factory reset, but it is still the same. Is this normal ? I never did not watch it, but because I fell stamina, so I do not know if it's workload tablet, or am I being paranoid ? :crying:

For activities that are not too CPU/GPU intensive - for instance reading web pages - it is quite typical for the screen to be responsible for 65-85% of the power consumed. On the Stock software, anyway.
If you make a claim that an improvement could be made in overall battery savings by changing kernels or ROMs, then you would expect the percentage of power used by the screen to INCREASE in those scenarios (assuming that the screen on-time & brightness was the same in a paired comparison).
good luck
PS. I'm pretty sure that each device in the tablet does not have it's own ammeter or current integrator - I'd hazard a guess that a great deal of "fudging" goes in to making up those individual power usage % rankings.

Thank you very much. The screen is around 80%, but other applications have only about 7% say it's okay. Thank you.