The accelerated expansion of the Universe has been established through observations of supernovae, the growth of structure, and the cosmic microwave background. The most popular explanation is Einstein's cosmological constant, or dynamic variations hereof. A recent paper demonstrated that if dark matter particles are endowed with a repulsive force proportional to the internal velocity dispersion of galaxies, then the corresponding acceleration of the Universe may follow that of a cosmological constant fairly closely. However, no such long-range force is known to exist. A concrete example of such a force is derived here, by equipping the dark matter particles with two new dark charges. This result lends support to the possibility that the current acceleration of the Universe may be explained without the need for a cosmological constant.