Abstract Recent evidence has shown that the mechanical properties of lithium-ion battery will change with the change of State of Charge (SOC) value. In this investigation, several quasi-static mechanical tests on 18650 battery cells with various SOC values were performed to reveal the SOC dependent mechanical behaviors and the voltage response of Lithium-ion battery. Experimental results indicate that the ability of Lithium-ion battery to resist deformation will increase with SOC value increasing. An explicit finite element model was established in HyperWorks/LS-DYNA with taking SOC effect into account.