This battery will keep my old Razr going for over 4 days. True, I do not use it much since the phone is for my overseas travel only (which is still once a month or so) and I use it primarily for local calls when overseas, but I often travel with this phone for a week without re-charging. I had used some other replacement batteries and, while they seemed good at the beginning, some even giving me better battery life than the Motorola, in the end they started dying early, discharged quickly and had to be replaced about 2x - 3x as often as this battery. I'll stick with the OEM product from now on.