The responses to your battery life concerns and ATK use have been answered in simply outstanding fashion.
I'll echo Adam74's comment and post above. I will also add to the comments by iamjoe by saying that these phones use a battery which actually lasts longer over time (lifespan, not runtime between charges), but giving it short "interim" boost charges whenever you are near a power source. For me, I have a car navigation dock and when I am in the car, the phone is on the dock and being charged. I carry both a wall adapter & cable, and also a portable power pack (*
RAVPower Dynamo-On-the-Go RP-PB07 Super High Capacity Power Bank (10400mAh Capacity / 1A & 2A Dual USB Output) for iPod, iPhone, Smartphones, Digital Cameras, Tablets and E-Books*), which are ready to jump into action at anytime. My office desk as the desk docking station and the phone is there during the working hours, unless I'm roaming around the office or out to an appointment.
By giving the phone even just one short (.5 - 1 hours), boost charge in the middle of the day when near a power source, it may be enough to bridge the gap and get you through the rest of the day without dying. Since these phones typically take from about 3 hours to as much as 5.5 hours to fully charge from a fully discharged state (my Droid RAZR MAXX has a 3,300mAh battery so it's 5.5 hours for me), you can do some quick and dirty math (best case scenarios and consumption rate averaging for illustrative purposes);
3 hours charge gives 16 hours runtime on a battery that's 1,750 mAh...
So 1,750/16=109.375 mAh/hr discharge rate...
And 1,750/3=583.33 mAh/hr charge rate...
5.5 hours charge gives 16 hours runtime on a battery that's 3,300 mAh...
So 3,300/16=206.25 mAh/hr discharge rate...
And 3,300/5.5=600 mAh/hr charge rate...
...And conclude that a one hour boost can yield from 3 to as much as 6 hours of extended runtime, and it is actually good for the battery as well. It is on the other hand very bad to run the battery down to the near zero remaining charge depths as this stresses the battery and WILL result in a shortened lifespan, as well as put you at risk of the battery and phone becoming unresponsive to a charger at some point due to deep discharging (white light of death, bootlooping, etc.)
