I purchased this battery in order so that I could fully cut my double-wide back lawn +front lawn. I often leave my grass on the longer side, so occasionally with my 4Ahr, I am only able to cut about 40% of the back. Now, I can easily cut all of my back +front yard with some charge left to spare. Keep in mind that if you live in high temp + humid areas as I, the stress will reduce the effective use time per charge. I live in Michigan and current temp is 90deg F+ 60% humidity.
This is the second 4amp battery. 1st has proved to be reliable, good quality, and reasonable run time. Would like a bit more run time but the 5 amp is sold out (usually) and the 6 is too expensive. Recommend the 4 amp as being a very good item.
I mowed my whole 1/3 of acre yard on this single battery. So far so good. I was very hesitant to buy an electric mower due to the size of my yard, but adding this third battery makes it all worth it!