I just got a LG-LS855 and it goes through battery kinda quickly. I read the manual on extending the battery like turning GPS, Wi-Fi, turning down the brightness and putting it in airplane mode etc. I was wondering if I could get a better battery for it from a different phone that would fit from Amazon or something like that. It is rated at 3.7V and 1500mAh.
Sorry for the inconvenience. I would suggest you to visit Sprint Service and Repair Center to have your device/battery checked and also get info about getting extended battery or possible replacement of battery with the specification that you mentioned above from our Store engineers.
Actually I got it from Ting, not sprint. It's a refurbed boostmobile so there's not much I can do about that. That's why I was asking if a different LG battery and back case is available to be used with it.