The hassle with wireless mice is that they can go through batteries as if they were crisp, delicious bacon. Some older models need their power sources changed regularly, and alkaline batteries aren't cheap. Here’s a clever solution. It replaces the disposable batteries you might be accustomed to using with a battery pack from a cell phone (in this case, a Nokia) with a much longer life.
As for how to recharge it, there are two solutions: either pop the battery back into the old phone and plug it in, or get your hands on an external charger. They’re easy to find online. Do be careful, though. Lithium-ion batteries are not toys.