Pat has a mobile mouse called the Anywhere Mouse. Leo says that mouse works on any surface. But Pat says it constantly shows a low battery warning. It comes with a recharging unit. Chances are the mouse battery is dying since it's five years old. There's only so many recharging cycles for those.
What's a good keyboard/mouse replacement? Leo says that Logitech works great. Pat should replace it with a model that lets him use AA batteries. Better yet, he could go wired. Leo uses wired mouses now because batteries never die, they're more responsive, and there's no risk for interference. And they're cheap!