Conventional internal combustion engine technology has been around for decades and historically has been the primary power source for virtually all industrial equipment. It relies on carbon-based fuels, is loud, polluting, and the machines it powers are expensive to operate and maintain. A self-contained, rechargeable battery system is provided that possesses improved power than comparable diesel and gas engines and it generates zero emissions, is virtually maintenance free, is quiet, and recharges overnight via a standard electrical outlet. The rechargeable battery power system can be installed in new and used construction equipment and may be used wherever a source of power is required including smart grid application. It can be safely used indoors, in neighborhoods and other locations sensitive to the side effects of internal combustion engines. There is a battery management system that controls sequential shutdown system and a power reserve system to control operation of the battery.