Hello,
i have a router that keep loosing its setting when ever there's a power down. the only solution is that the Cmos battery is flat but that cannot the case cause the router is a month old.
You don't mention a model number, so it's hard to know what might be happening. However, it would be unusual for a device like a router to have a cmos battery. From what you've said, it seems more likely the router is faulty.