<p>DC microgrid, as a typical strongly nonlinear system, contains constant power loads (CPL) with negative impedance characteristics and has a considerable impact on the stability of grid-connected operating systems. In response to this issue, the influence mechanism between the large signal stability of DC microgrids and the CPL carrying capacity was analyzed in this study. Specifically, the mixed potential function (MPF) analysis method was employed to analyze the large signal stability of the DC microgrid system. Then, the MPF model of the system was established under two operating modes of energy storage charging and discharging to analyze the large signal stability criteria, asymptotic stability region, and CPL load power constraints. The calculation formula for the maximum CPL power parameter of the system under both modes was derived. Furthermore, the Lyapunov energy function, energy function change rate, and asymptotic stability region of the DC microgrid system, were analyzed under energy storage charging and discharging operation modes by selecting two types of CPL power values that satisfied and failed to satisfy the criteria. The hardware-in-the-loop-based experimental results verified the rationality of the analysis.</p>