[HTC Amaze 4G] paperWastage:
after a few weeks of playing around with ROMs, tweaking and usage/behavior shaping, I can get mine to go around 12-48 hours (depending on usage)

Faux Kernel 012, Energy ICS stock 8/1/12, Data ON, autosync ON, 2 gmail accounts syncing gmail, Interactive Governor, top clockspeed set to 1.3ghz(instead of 1.5), -12.5 undervolt, brightness set to second lowest notch all the time

tl;dr of experience: (scroll down to see description of the problems)

Screen sucks a lot of battery (i set it manually to second lowest notch, get better battery life)

Problem with 100%->85% quick drain (1 hour)

Problem with battery drain (when going to deep sleep) after screen on for >5 minutes (see pics)

Problem with getting accurate battery reading(eg restarting phone sometimes gives 10% boost in the battery left indicator (see pics)

Screenshots of usage

on a regular "busy" workday with checking emails/some usage, I can get roughly 15-20 hours with 1-2 hours of usage

(when I got home, used the phone a lot during the commute home)

(the next morning without charging)

on a weekend (less email checking, less usage), I can get roughly 24-48 hours with 0.5-1 hour of usage

From CPU Spy, it shows that my phone is completely in deep sleep mode for most of the uptime (i did a reboot where the "spike" shows up in the previous picture, that's why it doesn't report 22 hours)... anyways, lets say 40% for 20 hours = 2%/ hours (remember, this is with data on and auto sync)

Description of Problems

Screen sucks a lot of battery (i set it manually to second lowest notch, get better battery life)

It just does.... Try this: Use your phone for 30 minutes screen on and use the device, but count how long it takes for the battery indicator to drop down by 1%.... at the second lowest notch, it drops down 1% every 5-6 minutes, which means 10% drop per hour (which is pretty good, as 10% = 200mAh)

Problem with 100%->85% quick drain (1 hour)

See screenshot below... on the first 15%, no matter what happens(screenshot shows device awake/screen on for the first part, but asleep for the second part), the battery %-left just drops off incredibly

Problem with battery drain (when going to deep sleep) after screen on for >5 minutes (see pics)

During screen on, I see that battery drains 1% every 5-6 minutes... okay... But after turning screen off, this drain continues for some time after... I've confirmed with CPU Spy that the device goes to deep sleep afterwards, so no idea why this happens

Problem with getting accurate battery reading(eg restarting phone sometimes gives 10% boost in the battery left indicator (see pics)

After rebooting, the battery %-left jumps up, as though it recalibrates... but this isn't accurate either (as you can see the sharp drop in battery %-left even though the device goes to deep sleep after rebooting)

Calculating usage with mAh

Anyways, if you calculate the actual energy capacity of the battery, my usage is pretty typical

Assuming a 1900mAh battery with 80% capacity (since we have to account for the 100%->85% inital drop)

For a workday (lets say 18 hour day)

Your Idle usage at 2%/hour means you use up 36% of the battery plainly on idle

80% capacity - 36%idle = 44% left

When you're using the phone, mine drops 1% every 5-6 minutes, so roughly 10% / hours

44% / (10% per hour ) = 4 hours.... but remember that my phone has the problem with the battery drain (from the pic, it looks like battery drain is twice the time screen on... so lets say 2 hours

This calculation says workday, 18 hours uptime, 2 hours usage.... My actual/estimated usage is 15-20 hours with 1-2 hours of usage from the screenshots above... pretty accurate

For a idle weekend (lets say 36 hour 2-day weekend)

Idle usage at 2%/hour = 72%. (probably less, since you don't receive as many emails)

Using phone at 0.5 hours = 5% drain...

80% battery capacity = 72% drain + 5% usage

pretty accurate from actual/estimated usage of 24-48 hours with 0.5-1 hour of usage

I guess once my phone's problem with the battery drain after screen on gets fixed, I can actually get 18 hour workday with 4 hours screen usage, that a few individuals in this forum get with their phone... Just no idea why it's like that.... since CPU SPy says the phone does go to deep sleep properly (like within 5s of pressing power button), I'm leaning on a bad Anker battery, or my phone's battery detecting hardware being faulty