So only hope to only get about 10 hours of use out of your phone? I just thought the battery was better than what I am getting. Maybe my expectations were too high. I would expect at least 15 hours of use.
Well, that's my personal opinion. I hope to get about 10 hours of usage out of my phone but I find I usually get 7-9 hours of usage which is still fairly good compared to others. (when i say usage, i mean the usage that shows up under settings -> general -> usage. My phone lasts me until the end of the day so I am alright with that; I just charge my phone every night.
Some people get 1-2 days and if that's all usage, I can't imagine how they can do that. if it's both usage and standby, it's still hard to believe but possible, i guess.
I personally feel 15 hours of use is too high of an expectation. Smartphones are big battery drainers compared to basic phones. The iPhone has a small battery too. The iPhone 5 has a 1430 mAh battery compared to the S3's 2100 mAh battery. For comparison, the phone I had before my iPhone 5 (it was a Samsung Gravity 2 and is a basic phone) had a 1000 mAh battery
if you are worried about your phone not lasting you until the end of the day; you can opt for an external battery pack and lightning cable or just bring the brick adapter and the lightning cable around. You can go for battery cases too if you want but I don't like them because they're more expensive than battery packs