In　this　study,　a　new　bidirectional　boost　converter-　based　battery　state-of-charge　(SOC)　active　equalization　system　via　an　adaptive　backstepping　sliding-mode　control-based　balancing　strategy　is　proposed.　The　system　configuration　and　modeling　are　developed　by　analyzing　the　equivalent　circuits　of　the　battery　and　bidirectional　boost　converter.　An　adaptive　backstepping　sliding-mode　control　with　the　balancing　selection　strategy　is　subsequently　applied　to　implement　the　regulated　charging　and　discharging　of　battery　cells,　which　possesses　the　capability　in　addition　to　against　the　external　disturbance　as　well　as　parameters　variation.　Finally,　a　comparative　simulation　for　battery　cells＇　equalization　according　to　the　same　balancing　strategy　between　the　proposed　bidirectional　boost　converter-based　system　and　the　typical　top-down　equalization　scheme　is　carried　out,　and　the　results　indicate　that　the　proposed　system　can　shorten　the　equalization　time　about　9.8　%.　©　2019　IEEE.