The carrier dynamics in InAs double-cap quantum dots DC-QDs grown on InP113B are investigated. The shape of these QDs can be controlled during the growth, yielding an emission wavelength of the system of about 1.55 m at room temperature. The DC-QD dynamics is studied by time-resolved photoluminescence experiments at low temperature for various excitation densities. A simplified dynamic model is developed, yielding results consistent with experimental data. This analysis yields the determination of the Auger coefficients and the intradot relaxation time in this system.