Obviously I'm not being literal about the size, but the running capacity has stayed poor since the beginning of the era. Cell phone manufacturers have tricked us for years by advertising the "standby time" and kept the focus away from the "talk time" and now more important "screen on time". Sure, my Samsung Galaxy SIII can standby for a week without using it, but 3-4 hours with the screen on and you'll find yourself begging for a charger. Of course the Galaxy SIV and the iPhone 5s are the current models, and are better then my example, but not by a lot. Each new device model increases in processing power, and with the advancement in app graphics and function comes higher battery demand. The way I see it, these devices are designed to operate from one plugin to the next. Cellular phones have become a lifeline of our social and professional lives and should be able to stay on, while we're on. Having to plug your phone in at night is totally reasonable and should be encouraged. If you can purchase a phone with different colors, processors and memory capacities, you should be able to pick battery life too.
Don't worry, I'm here for you. I wouldn't waste your time letting you read this if I didn't have a solution. Take a look at extended batteries. As an example, my Samsung Galaxy SIII battery is 2100mAh (the higher the better) and this ZeroLemon 7000mAh extended battery clamps on to the back of my phone and puts my 4 hours of screen time to around 15. That means I could literally have my phones screen on all day and not worry about battery life. Now, if phone girth or cuteness is a major factor for you, consider a more conservative option. Batteries are big and heavy so if you want big power you are going to sacrifice something.