After I charged both batteries for the first time, I thought I would need both batteries to vacuum my family room. I have 2 dogs & 5 cats so you can imagine the hair that may accumulate if neglected. I love the ease of no electrical cord to drag around or trip over. This little power vac picks up all the dander & hair from the carpet & throw rugs with out moving them around. You will have to empty the canister more often, obviously because it's half the size of a big vacuum. It's so light weight, I was surprised how much debris it collected for it's size. I finished my family room and my battery pack was going strong so I continued vacuuming the hallway... bathroom, then the living-room... dining-room... kitchen (also equipped to vacuum bare floors)... and finally slowed down at the stairs. So essentially, one battery was enough power to clean the entire bottom floor of my house, about 1400 sq ft. So, I rotate the batteries each time I vacuum to keep the batteries functioning well. Best stick vacuum for your money!