This study is aimed at developing a low cost lumped model for simulating a Li-ion battery pack with thermal management systems (TMS) under continuous charging/discharging cycles. The considered system is composed of twenty-four commercial Li-ion batteries with phase change material (PCM) and nine aluminium tubes for liquid coolant circulation. A zero-dimensional numerical model is developed based on the transient energy balances and the analogy between heat transfer and electrical transfer using resistances and capacitors. The simulations were carried at 3-C discharging/0.5-C charging rates and obtained results were compared with both three-dimensional computational fluid dynamic (CFD) results and experimental results from the literature. The effect of various system design and operating characteristics such as the cooling method, the coolant temperature and its velocity, the number of coolant pipes and the ambient conditions on the system performance were presented and analysed. Results show that combining both PCM and liquid cooling for battery thermal management leads to reduce the maximal battery temperature by about 38 • C and 4 • C compared to natural convection thermal management mode and to passive PCM thermal management mode, respectively. Increasing the number of cooling pipes improves the performance of the system and its optimal number in this system is up to 9 pipes. The maximal battery cells temperature is reduced from 31 • C to 20 • C as the used liquid coolant inlet temperature is reduced from 25 • C to 10 • C. Finally, the suggested low cost lumped model is a promising tool for simulating, designing and optimising battery pack with thermal management systems under real exploitation conditions.