Lithium ion battery is the most popular used portable energy storage technology due to the relatively high energy density. While the thermal instability induced safety concern impede the pace of marching large application, which has no tolerance for the catastrophic failure. At off-normal operation, one or more side-reactions would become the main factor induce continual temperature elevation, which in turn accelerate the reaction rate and possibly lead to catastrophic thermal failure. There is divergence point between runaway behavior and normal thermal failure, which can be used to estimate whether battery can get catastrophic failure. This critical condition also can be used to explain and predict the thermal runaway propagation between cells. In this study, we focused on the interest of the thermal critical condition that leaded by one or more side-reactions using non-dimensional analysis method. The reactions used Arrhenius approximation: R=Acⁿexp(-E/RT). Through nondimensionalization of energy balance equation, nondimensional critical parameters such as critical criterion, critical temperature were obtained. And the nondimension stationary energy balance equations of battery thermal failure under Semenov model and Frank-Kamenetskii models were employed:ψf(θ)=θ, d²θ/dρ²+jdθ/ρdρ+δf(θ)=0. These critical parameters shows the critical condition of battery catastrophic condition correlates with cell's configuration, size and thermal characteristics of side-reactions. Under the boundary condition of two thermal abuse models (Semenov, Frank-Kamenetskii), the critical criterion (ψ, δ), critical temperature distribution (θ) and delay time of thermal runaway (τ) were analyzed in different cell deformation, capacity and thermal characteristics of side-reactions. These critical parameters are also calculated according to the thermal characteristic parameters from literature, and the results compared with the computational analysis and experiment works in literature.