[cappy]

Consider this
Both you and your friend have identical corvettes. He filled up two days ago and so did you. He calls you today and tells you that he is out of gas. "I can only go two days on a tank of gas! What is going on?" Of course, you have a half tank of gas left and tell him that is not right. "You should get at least 4 days on a tank of gas." Take this analogy a step further. He says "This happened to me last week too. So I turned off the radio and the car seems to go a little further. But I am still only getting 2 days on a tank."

Anything wrong with this discussion? Wouldn't you need to know a little more before concluding that it is his car that is causing the problem? That is why when we measure a car's energy use we report in "miles per gallon". Now apples can be compared to apples.

Since you know that both cars have an electronic readout that reports miles per gallon, you ask him "what is you MPG reading?" He says "15mpg". Your reading is 15mpg too. Now you know that the cars perform the same. Upon further investigation, you learn that he has been driving from Washington D.C. to New York City each day. You only go to the grocery store.

If you get 15 mpg and he gets 10 mpg, you can begin to find out what is causing the difference. Maybe he has a leaking gas tank, may his fuel system is dirty, maybe he leaves his car idle for 2 hours each morning. Or maybe he sits in traffic for 2 hours each night. Once you find the source of the problem, you can correct it. If it is the leaking gas tank, you get it fixed.

If you get 15 mpg and he gets 14mpg, you might be looking at tire inflation or air conditioning, etc. You would just need to "tweak" the car. But a tweak will not help much if your gas tank is leaking.


Moral: If you want to improve battery life, you must measure your battery drain properly.

Steps to follow if you want to understand your bad battery life
Some good data and useful anecdotal information has been posted in the many pages of this thread. So much, in fact, that it may be more confusing than helpful. For those who came here to find out more about what that guy knows who knows "why battery life sucks so much!" you got 1,000 answers but maybe no concrete solution to your battery problem.

Having read all of the information here and having observed various readings on my Diamond for more than a week, I offer a two step procedure to help you decide whether you want to hock your Diamond or keep it on your finger. Following these steps may not solve your battery problem, but if you follow the steps you will understand your problem better. In the end, you may learn that you have defective hardware or a defective battery. You may learn that your weak radio signal eats too much battery.

Or you may learn enough about what causes your dramatic battery drain that you can take steps to solve the problem. Even if you can match the results of my device, it is only the first step unless you do not use BT or Wifi or push email. These I think have their own issues that need to be tested separately, one by one. I only report my results for Phone radio On, and everything else off. If you cannot match my battery life with these settings, there is no point in wasting more time.

What to Expect
With my Phone Radio On and everything else Off, I can expect to lose 1% to 1.5% per hour of battery life. After 10 hours, my battery reading will be 85% to 90%, with no use. For each hour of talk/data time, I will lose an additional 20% of battery. So if I talk for 45 minutes and spend 15 minutes on the Internet during the day, my battery will read 65% to 70% at the end of 10 hours. After 24 hours with one hour of talk/data time, I will have at least 45% to 50% battery remaining.

If you follow the steps below, you will either see the same results, or you won't. If you do not see the same results, at least you should have some clear idea of where your device is going wrong. Because I started out with good battery life and have optimal signal strength, you can at least use my results as a benchmark to compare to your own device.

Step One
If the comparison to my device is to be meaningful, you need to make your device look as much like mine as possible in the areas that count. I recommend that you install 5 programs. As a disclaimer, I have no interest in any of the programs, but I find them useful. The programs are listed below without links. I will try to edit this post later to add the links. You should be able to find references and links to all of the programs within this forum.

The first two will allow you to get registry settings similar to mine.

Diamond Tweak - optional
Advanced Config - optional

EDIT: Upon further analysis, I do not think that it is necessary to install these 2 programs, though some of the tweaks contained therein may be helpful. I have uninstalled both and have observed no measurable change in battery life. So you can skip the next paragraph if you like.

Install the above programs. First run Diamond Tweak and then Advanced Config. Each program has recommended settings for each field. Follow their recommendations. Installing both is probably redundant. But that is what I did when I first got the device. If you do the same, then your registry will be similar to mine.

The next three programs will allow you to read the battery level and discharge rates as I do on my device. There are other ways to do it, but if you install these programs, you can follow the same method that I have been following to monitor the device.

NuePower - used only to supply 1% battery level readings
Second Today - used to hold Homescreen Plus plugin and view readings
Homescreen Plus - displays battery level, CPU load, and mA discharge rate

Link to NuePower: http://www.nuerom.com/BlogEngine/page/nuePower.aspx
Link to Diamond Tweak: http://forum.xda-developers.com/showthread.php?t=409540
Link to Advanced Configuration Tool: http://www.touchxperience.com/
Link to Second Today/Homescreen Plus: http://www.chi-tai.info/cs_wm_tools_im_cs.htm

This is not the place to go into the "how to's" of installing the programs. You may need to do a little reading and research. There is plenty of information out there and threads dedicated to each. When you are done, you should still have TF3d, but will able to switch to the Second Today screen easily. Homescreen Plus is a plugin that can be added to the Second Today screen. It will give you readings for battery level, CPU load and current discharge rate. You will use these readings to monitor your device.

Step Two
Once the above programs are installed, the registry settings are made and you can easily switch between TF3D and Second Today, you are ready to start monitoring. First, fully charge your battery. Even fully charged, it will probably quickly go to 96% or 97%. Don't worry about that. When fully charged, soft reset just to be sure that you are starting clean. Then go to Settings and turn off all except the Phone Radio. For now, make sure no programs are set to automatically access the Internet. Also, as tg1.0 has suggested, turn off the Password option before you do the soft reset.

Switch to the Second Today Screen. Your battery level should be 96% or 97%. Your CPU load should be 0% to 1%. Your mA discharge rate should be 57mA at the lowest backlight. If you have the light sensor on, it will probably be 75mA or 84mA. Give it 30 seconds or so and it will go 57mA.

If you see the same readings, great. Just turn off the screen. Every once in a while (I recommend at least every hour), turn on the device and go to the Second Today screen. The readings, after a few seconds should be exactly the same as stated in the last paragraph. Each time that you look at the Second Today screen, YOU SHOULD SEE THE SAME READINGS.

Don't be afraid to use the Phone or access the Internet. But each time, go back to the Second Today screen. The readings should settle down to the same as stated above. Be sure, for now, to turn off the Data Connection after using the Internet. There was one occasion where the CPU load stayed above 1% after a long phone call. This is a problem that I have not tracked down and it will cause excessive battery drain. If this happens to you, soft reset and continue monitoring. The goal right now is to get a picture of how the battery can perform through the day.

IF YOU SEE THE SAME READINGS ALL DAY, AT THE END OF 10 HOURS YOU SHOULD HAVE 85% TO 90% ON THE BATTERY, ADJUSTED FOR TALK/DATA TIME.

IF YOU CANNOT GET THE READINGS ABOVE, TAKE TWO ASPIRIN AND CALL ME IN THE MORNING.

GOOD LUCK

Update 10/15/08: I hard reset a few days ago and have not re-installed Advance Config or Diamond Tweaks. I have been monitoring the battery, as described above, but have turned on the Data Connection. As long as the Data Connection is dormant (greyed arrows), there is no measurable difference in my battery life. Of course, when the connection goes active (white arrows) there is a substantial difference.