[AT&T Samsung Galaxy S II Skyrocket SGH-I727] kr3w1337:
I want to share my setup with you guys for getting good battery life which lasts the day without making you compromise on the features. The primary things I've seen on the forums so far has a lot of involved setup and frankly by the time you get it perfect, you will flash a new ROM and have to re-do a lot of it and so on, overall it's not the worth the hassle.

This is usually what my days look like and I manage to last the entire day:

I keep wifi and GPS on always, regardless of whether I'm using it or not.

Get a fair bit of calls because I live away from family so they all call a lot (I have a massive family, so we are talking about 5-6 hrs of talking everyday).

I like to read news from news republic and I'm subscribed to a lot of stuff there so I go through like 2000+ articles in a given day.

XDA like every few hrs (damn ICS!).

Text messages are also flowing throughout the day with the woman being on the other side of the country and all (100+ a day?).

I have facebook on push (not an addict but active enough to mention)

My gmail, school and exchange are all on push for email so they I see a fair bit there

The setup is VERY easy to setup and replicate. It doesn't require you to lose out on features or use your phone at an anorexic level either. You don't need a task manager or watch your processor non-stop either.

So without further delay, here we go:

Pick a ROM

I'm using Seanster_GBaxe EX v1.5.1 from the T-Mobile section, you can find it here.

Get faux's kernel

The reason for this particular one is because it's given the best results when it comes to undervolting and overclocking without SOD. You can find the kernel here.

Get System Tuner

This is available on market. There are alternatives but for this post, I will be making all the references from this app.

Get the AGPS patch from crypted

This isn't for battery directly but it does get locks VERY fast and you waste less clock cycles getting the signal. Less clock cycles wasted, more battery saved. The patch is available here.

I personally use the v3.0 Google CWM Build (scroll down his post and you will see it)

Get the V6 SUPERCHARGER from zeppelinrox

This is available here. Why the beta one? It works fine.

Okay, at this point you can pretty much store these things together in a neat little folder on your SD card because it makes a perfect library. So let's get started, I'll assume that we are starting from scratch. The order for everything will be as follows:

Get into recovery and install your ROM

This I shouldn't have to explain, the instructions you can find on the ROM thread.

Install the kernel

Same with this, read the kernel thread.

Install the GPS patch

Same with this as well :)

Boot into ROM

Hmm.... hopefully you can manage this

Restore all your backups and apps, accounts and whatever else

Using titanium here is always good

Install System Tuner

Okay, let's get started. Although faux has done an amazing job with the kernel, there's always the personal bias that goes into making things so his balanced settings might not reflect yours (nor mine but you will be tweak even those soon).

Inside System Tuner, go to CPU:

The first you thing you should choose is whether you want to keep the 1.72 GHz OC or not. I kept it but if you want to get even more you can lower to stock 1.56 GHz or go even lower, your choice. Once you set the max, set the min to 384 MHz. Set it once and you don't need to do it again after. Leave the governer to ONDEMAND.

Now go to the Voltage tab:

Be careful here, this can crash you if you go too far. What we do here is globally undervolt, you can do that by hitting the -12.5 mV button over and over. I use -75 mV (press the button 6 times, for those bad at math). Keep in mind that all chips are NOT THE SAME!!! -75 mV might be too much for you or you might even be able to get to -100 mV, find out by doing it.

Now go back to the CPU tab and hit Boot Settings:

Hit Screen-off behavior:

Governor - No changes

Max frequency - 384 MHz (push doesn't lag at all still so don't worry about notifications)

Max frequency/in call - 384 MHz (yes, calls don't require full blast, they work fine even under 500 MHz)

Now go back

Hit Governors behavior:

Sampling rate - Unchanged (faux has it done perfect)

Up-threshold - 75 (what's this? This means that the CPU will scale to higher frequencies when the load is above 75%)

Power-save Bias - 70 (what's this? This means that the CPU will be "biased" towards lower frequencies when load is below 70%)

Setting the Power-save Bias higher than the Up-threshold is obviously stupid so make sure you did it right.

Now go back

At the bottom, there is a whole bunch of tweaks:

Hit Re-apply CPU settings, choose init.d script (you can choose boot too but init.d works 100% of the time)

Hit Boost app loading, choose init.d

Hit Clear cache, choose init.d

Now go back

Find the Startups section and disable whatever you don't want running at boot (this is purely a personal thing).

Install V6 script

His instructions are very good so I'll assume that you have gotten it installed. Once you have it running, choose option 9, the 1000 HP one. Reboot. Run script again, make sure you've got it at 100% supercharged. Done. Reboot just to be sure again.

All done! Now, I know that was lengthy but here's the awesome part. Make a titanium full backup of System Tuner and you NEVER have to do that again for ANY ROM as long as you use the same kernel!! The script is unfortunately the only thing you have to re-apply, probably that has a quick setup too but I'm new to it so I can't give you shortcuts on it.

Hope you have luck with this and it works for you. I promise nothing and if you break your phone please don't come crying to me because you chose to do this yourself. It works for me so I shared it!! Any suggestions are welcome of course.

Note: NO task manager required!! I will modify this for cm7 if needed.