I finally figured out how to get my battery to stop draining fast while my Optimus V is in standby. Usually it would lose about 20% battery overnight. That was unacceptable. haha
I downloaded an app called SetCPU, and set up a profile that underclocks the CPU to 122 MHz whenever the screen is off.
That helped, but the battery still drained pretty fast while it was in standby. I noticed that underclocking the CPU to 122 MHz while it's in standby makes the phone charge a lot faster.
I figured out that it was the 3G data connection that was killing the battery fast. I have Wi-Fi in my house, and that uses a lot less power than the 3G connection on the phone.
By default, Android puts the Wi-Fi connection to sleep while the display is off for a few minutes.
This is a REALLY bad idea. I changed the Wi-Fi sleep policy to "Never", so Wi-Fi always stays connected. I just tested it last night, and my battery stayed at 100% without being plugged in! NICE.
To change the Wi-Fi sleep policy, go to Settings --> Wireless & Networks --> Wi-Fi settings --> (phone menu key) --> Advanced --> Wi-Fi sleep policy --> "Never".
Here's a screenshot to prove it (I used the phone for a few minutes in the morning, so it dropped from 100% to 96%):
http://img708.imageshack.us/img708/1976/screenshot1314202286552.png
I'm also thinking about buying an extended battery that's 3000 mAh (the stock battery is 1500 mAh).
3000 mAh battery - Android Forums
A few people on that forum post claim the extended battery lasts for 3 to 6 days. That sounds great. With these settings I changed to fix the standby battery drain problem, I bet I could get the extended battery to last even longer.