The　purpose　of　this　present　study　is　to　prepare　a　stable　mineral-oil　(MO)-based　nanofluid　(NF)　for　usage　as　a　coolant　in　a　transformer.　Nanoparticles　(NPs)　such　as　hexagonal　boron　nitride　(h-BN)　and　titanium　oxide　(TiO2)　have　superior　thermal　and　electrical　characteristics.　Their　dispersion　into　MO　is　likely　to　elevate　the　electrothermal　properties　of　NFs.　Therefore,　different　batches　of　NFs　are　prepared　by　uniformly　dispersing　the　insulating　h-BN　and　semiconducting　TiO2　NP　of　different　concentrations　in　MO.　Bulk　h-BN　NP　of　size　1　mu　m　is　exfoliated　into　2D　nanosheets　of　size　150-200　nm,　subsequently　enhancing　the　surface　area　of　exfoliated　h-BN　(Eh-BN).　However,　from　the　zeta-potential　analysis,　NP　concentration　of　0.01　and　0.1　wt.%　are　chosen　for　further　study.　The　thermal　conductivity　and　ACBDV　studies　of　the　prepared　NF　are　performed　to　investigate　the　cooling　and　insulation　characteristics.　The　charging-dynamics　study　verifies　the　enhancement　in　ACBDV　of　the　Eh-BN　NF.　Weibull　statistical　analysis　is　carried　out　to　obtain　the　maximum　probability　of　ACBDV　failure,　and　it　is　observed　that　0.01　wt.%　based　NF　has　superior　cooling　and　insulation　properties　than　MO　and　remaining　batches　of　NFs.