Sounds like you have something running in the background without you knowing. I have a couple suggestions for you.
1) If you want to spend time trying to figure it out, overnight leave your phone in Airplane mode. You won't get calls or texts, but if you're not using music or other apps, power consumption should be minimal. If you don't drain nearly as quickly as now, it's mostly likely one or more apps running in the background.
I've found that some apps simply restart themselves when there's a change in phone status (screen unlock/awake). Flikr and Facebook always seem to turn themselves on even though I've never used them and don't have accounts with them. When they turn on, they also turn on/use GPS. That forced me to have to check to see if GPS was on.
I cannot figure out why, but something was also turning on my bluetooth. That's been resolved, but it was draining the heck out of my battery.
Go into your apps and make sure you're not giving them permission to do things with your location (via GPS) and that your background data doesn't continuously refresh, rather it refreshes only every hour or when you direct it to manually.
2) Based on the % you indicated, 44% cell standby would be the only thing that seems high. Is your cell signal strenth good? Standby could be affected if you're in a low-signal area as it forces your phone to work harder to establish and maintain network connection.
