The collision and separation of waterdrops at their relative terminal velocities are shown to be accompanied by the formation of a filament of liquid between the drops. In an electric field the electric charge on the two drops after separation is a function of the filament length. The theory of Latham and Mason (1962) for the charge transfer between cloud particles in an electric field E at angle ϑ to the line of centers is applicable only to rigid spheres, whereas that of Censor and Levin (1973) uses an idealized model of waterdrops separating with a filament between them. Experimental measurements were compared with the two theories, and it is concluded that the charge transfer is adequately described by Q=αnEr2cosϑ¿9¿1011 C, where αn has been determined for certain values of the drop radius ratio R/r and the nondimensional length of the filament n.