how long is charging time vs. run time?

This product uses nickel-cadmium (Ni-Cd) rechargeable and recyclable batteries. When first taken out of the box the battery must be charged for 24 hours before use. After reading all of Lowe's and another 100 or so reviews nobody ever stated that the vacuum battery ran out of power. It seems as if they also keep it plugged into the wall when their not using it. This is a very nice portable vacuum.