Batteries

Simply put your stock battery is the best battery made for your phone. It is lithium ion and uses the newest technology formula to get the most life out of a battery that size. Those other batteries that are listed as 1500, 1600, 1800mAh are not what they say. The regulation on how they are rated is not strictly written.  Manufacturers can almost put whatever they want on the label. To top it off they may not even be of the same quality as your oem battery.

Think of it the same way as the fleamarket type car stereo equipment. You pick up a pair of speakers that are listed on the box as 1000watts. They look cheap, sound like crap, and sell for only $10. So how can the manufacturer call them 1000watts? Because they can through some marketing loophole. If they were rated the same way pioneer or kenwood would rate them, they would most likely be rated at 10watts.

So basically the batteries are not what they claim. But yeah for $10 you can get 2 batteries and a charger. And if her oem battery goes dead she can always swap one of them in to get her through the day.