The utility model discloses a portable direct -current emergency power source, including shell and electrolyte reservoir, the shell is hollow structure, and electrolyte reservoir is located the inside middle -end of shell, peg graft and have extreme post in electrolyte reservoir's upper end, the upper end of extreme post is run through the shell and is lain in the top of shell, the both sides outside of protective layer all is equipped with air bag, and air bag's lower extreme and diaphragm fixed connection, air bag passes through the protection shield and is connected with the shell, the lower extreme of shell is equipped with the rubber antislip strip, and transversal half circular that personally submits of rubber antislip strip, the equal embedded handle that has in the outside both ends of shell not only can be so that the power be convenient moves, but also can be at the in -process that moves, avoids external force to electrolyte reservoir's destruction, and the harm that prevents electrolyte reservoir and cause because of vibrations has lengthened the life of power, economical and practical.