The battery life depends on usage. The average customer using a DC15 (3rd Gen) could get up to 4 - 6 hours on a single charge. Some businesses may want to consider a second unit or battery to reduce downtime while the unit is charging and to keep busy operations efficient. Overall, it's a great piece of light duty equipment that runs off a lithium ion battery (24v) and charges fast. The DC20 runs off a lithium ion battery (48v).