It appears that the Optimus V suffers from the same
GSM/CDMA auto prl cell standby bug that affects the Evo's battery life.
To check if this bug is affecting your phone, go to AboutPhone -> BatteryUse -> CellStandby and check to if there is an entry for "Time without a signal". If your phone has a solid signal to Virgin Mobile at all times, it will read 50 percent.
To fix the issue, dial *#*#4636#*#* and it will load the testing screen. You do not have to press call. Select phone information.
My understanding of the bug is that even though the preferred network is set to "CDMA auto (PRL)", it is actually set to "GSM/CDMA auto (PRL)" because of a display bug.
The fix is to press Menu and then "Select radio band". The process will then force close. Go back to Phone info and select "CDMA only" and then select "CDMA auto (PRL)".
To verify that this fixes the issue, charge your phone to reset the battery statistics. Unplug the charger and check back in an hour or so. It should no longer say time without a signal (assuming you are in an area with a strong signal strength). This should cut the cell standby battery usage in half. The fix is not permanent. If you reboot the phone, you will have to make the changes in the testing screen again.