Average battery life of 3GS?

Let me clarify. How long should the battery last if left completely idle in Airplane Mode with no usage of apps or anything else?

I see your point, thanks. I appreciate that there are a huge number of usage and configuration variables among users. I was hoping to find some kind of benchmark against which to judge whether the rate of drain I am experiencing with mine is reasonable.

For example, aside from the tech specs quoted in the product literature, what could one realistically expect of a new, out-of-the-box iPhone, fully charged and updated to the most recent OS but "off the grid" (i.e., airplane mode) and idle? I could then take that data and extrapolate it based on the age, usage, number of charges, etc. of my current iPhone.

If I fully drain and then charge the battery, and then leave the phone in airplane mode and don't use it at all, the battery is dead in 8 hours. That just doesn't seem right (or reasonable) to me.

DFU? Sorry, not familiar with the acronym (though I feel a huge "duh" coming my way...)

Thanks. I'll try it.

Thank you for sharing your experiences, Alain. At this time I have a replacement 3GS while Apple tries to figure out the problem with mine. In all likelihood I will probably end up keeping the replacement. Before iTunes would allow me to restore from backup on the new/replacement phone, I had to upgrade the OS to 4.1.

The first night, the battery was 100% and I left the phone on all night (not in Airplane mode, Bluetooth off, push notification for mail off) and I had 30% battery life left after about 8 hours. It's an improvement over what I had been experiencing on my old phone, but still not ideal by any stretch.

I will heed your advice and on this phone I won't open the Game Center. I'd like to delete it altogether if I could!

If the battery drain worsens on this new phone, I will try resetting and restoring as you suggest, though I found that the apps don't restore properly if you have any folders, and it's a PITA to reorganize them.