The specific heat capacity of a battery is an essential parameter for the thermal modeling of lithium-ion batteries, but it is not generally provided by the manufacturers. To determine the specific heat capacity, equipment such as calorimeters can be utilized which is costly, whereas this paper proposed a novel method to determine the specific heat capacity that only requires conventional equipment, which is easy to find. The specific heat capacity is determined under a forced convection environment by introducing a heat loss compensate model. With this thermal compensation model, the test results wave near a constant (1044 J kg−1 °C−1) regardless of the time change. To validate the method, an aluminum alloy block with the same shape as the cell is used. Results showed a specific heat capacity of 867 J kg−1 °C−1 with a 3.3% error compared to the reference value of 897 J kg−1 °C−1. In addition, to verify the stability, repeated independent experiments were carried out and the results showed that this method has a good consistency. This novel methodology presents an effective way to determine the specific heat capacity at a lower cost and can be achieved quickly.