Today, creating sustainable development by reducing environmental pollution has become a vital issue for humanity. The polyethylene films for battery separators contain almost 50 wt. % of nanosilica therefore, which makes them a good candidate source recycled nanosilica. The primary goal of this study is utilizing the recycled nanosilica from battery separator in NR/SBR nanocomposites to improve the mechanical properties. The NR/SBR nanocomposites with 20 and 40phr recycled nanosilica were prepared using two-roll mill and internal mixers and their rheological and mechanical properties were studied. The scorch time is increased with recycled nanosilica content, while the cure time showed an optimum value in the sample having 20 phr nanosilica. The same trend is observed in mechanical properties. While the modulus increases with nanosilica content, the tensile strength reaches an optimum in 20 phr of nanosilica. In other words, the nanocomposites with 20 phr recycled nanosilica, have an increase in tensile strength by 27%, modules by 76% and hardness by 36% compared to the neat NR/SBR sample. Finally, this study finds a suitable application for nanosilica recycled from battery separators in NR/SBR nanocomposites and suggests a sustainable approach for battery waste management at low cost and reduced environmental damage.