I just switched from a GS3 to a new Note 3, and I am astonished by the battery life. I purchased an extra battery assuming that I'd need it, but a week in- I have not needed it once. By the way- I purchased my spare (stock) battery from Verizon for $35 or so. I will only purchase batteries from an authorized retailer since I literally could not purchase a real Samsung spare battery for my previous Samsung phone any other way. I bought several through eBay, Amazon, All4Cellular, etc and all turned out to be counterfeit. Anyone who has purchased a battery from a source other than their mobile phone service provider or the manufacturer (in my experience / opinion) very likely has a counterfeit battery which may or may not work well.