I think that's not a problem these days at all. i have a bunch of battery tools and they all last plenty of time. For a blower I figure a good hour of operation per charge wouldn't be unreasonable. As an example, the usual flight time for RC airplanes is 15 minutes with the cheapest batteries. The reason why is became the charge and discharge rate is usually around 1C which is about 15minutes for the now 20 years old lithium technology. New battery tech is better. I've seen charge times close to 5 minutes now.