I had a very old Nokia for ages, that even when I replaced it with the phone I got when I started working, that had a battery that could go for 'at least' one week. I used it solely for calling and messages, which is all it could do too, no camera, no colour screen, nada! Loved it ...
Then I got my first iPhone, a 3G, battery life was down, I left Bluetooth, Wifi, 3G on all the time. I was constantly interacting with the phone which as anybody with an app-ridden iPhone knows, kills your battery in terms of minutes to one hour ...
Then I adapter to how to use a phone that can do a lot, just dumb it down a bit. Bluetooth I never use, so that's constantly off. At night I turn it off, as I don't need the radiation next to my head (and I do use it as my backup alarm clock so ...), 3G I turn off when I'm at the office, since I'm usually at my laptop, same for Wifi, which is almost never on. And on top of that, I dim the screen ever so slightly.
Combine that with a charger in my car, I have a daily recharge in the evenings, which suits me fine.
Battery life of my telephone isn't important that way, it's always working when I need it, I tend not to forget charging it, so I really don't bother.
Conclusion: I don't know what to answer here, what is the expectancy of my phone with one full charge? No idea, I'm not waiting till it runs out of juice, to charge it ... I bet it could be anywhere between one of three days for the 4G I have now. But who knows ... and more importantly, who cares.