There is no need for power or batteries with a heat-powered product, but typically they will have more features than their battery-powered counterparts. For example, many of them can also be used in your BBQ grill which makes it even easier to monitor everything that’s going on! Similarly, if there is any problem with electricity then these units won’t stop working like some cheaper versions might either (this isn't an issue we've found though). They do require maintenance every now and again though so you will want to check them from time-to-time.