Concerning about integration and high efficiency of topology, nonisolated multiport converters are widely researched in low power Energy-Harvesting-battery (EH-battery) systems. However, the pulse width modulation (PWM) based nonisolated multiport converters usually have the shortages of larger number of switches, ports' voltage restrictions, hard switching, time-sharing transmission of energy and poor compatibility of MPPT algorithms. Therefore, in this article, a transformer-less multiport converter based on LLC and bidirectional buck/boost converter is proposed, which has the ability to step up and down voltage and well compatibility of MPPT. Meanwhile, soft switching technology is applied so that the converter can work in higher frequency and has smaller size. In addition, the energy can be transmitted simultaneously with the control of PWM and pulse frequency modulation (PFM). Finally, the experimental results of the proposed topology and its comparison with several topologies are given to prove the characteristics of the proposed converter.