Not every jobsite has electricity to power up your rotary hammer. In many cases buying a cordless rotary hammer is the only way to go. In reviews posted online in power tool forums and websites the NENZ NZ80 Litheon 20 Volt Lithium-Ion 1-3/16-Inch SDS-Plus Rotary Hammer gets the top nod from experts and owners alike. The battery powered 20 volt rotary hammer is lightweight enough to work with all day and not suffer from arm fatigue. The Litheon batteries give you the freedom to work without a cord getting caught on things or just being in the way. Some studies have shown that the NENZ cordless rotary hammer is up to 60% faster than other comparable models. Owners say the variable speed trigger supplies the utmost in control and the integral clutch provides consistent performance. Features 1 inch maximum capacity in concrete, 1-3/16 inch in wood and metal. The unit comes with 2 batteries so you can always have one charged and ready to go. Charging time is roughly 1 hour - or 80% capacity in just 25 minutes time. One owner describes the cordless NENZ NZ80 as "smooth, quick charge and durable". You can view all the top rated cordless rotary hammers in the website here.