8-10 hours
Generally, the design of the electric drill product is a single charge time of eight to ten hours, you can pay attention to the charger indicator light has no change, it may be the red light to green, it may also be blinking to steady on, the light is fully charged, and then unplug the charger for about half an hour.
With a 6 mm diameter drill bit and a hole depth of 5 cm, the 4000 mah 42-volt lithium battery can punch between 38 and 50 holes in the concrete main beam. 12A large battery pack between 300 and 400 holes. However, there is a 2-meter wire connection between the battery pack and the electric hammer, with a quick connector, and there is no problem in working on the site for a day. Heavy electric hammer is best with battery pack, such as with a small battery is easy to heat, short life, because the heavy electric hammer starting current is large. The working efficiency is twice that of the lightweight rechargeable hammer. Battery fees paid a lot, 12 small batteries can not top a battery pack. The starting current of heavy electric hammer and light electric hammer is not the same, and the number of holes will be slightly different.