  We derive the dual CFT Virasoro algebras from the algebra of conserved
diffeomorphism charges, for a large class of abelian Kaluza-Klein black holes.
Under certain conditions, such as non-vanishing electric and magnetic monopole
charges, the Kaluza-Klein black holes have a Reissner-Nordstrom space-time
structure. For the non-extremal charged Kaluza-Klein black holes, we use the
uplifted 6d pure gravity solutions to construct a set of Killing horizon
preserving diffeomorphisms. For the (non-supersymmetric) extremal black holes,
we take the NENH limit, and construct a one-parameter family of diffeomorphisms
which preserve the Hamiltonian constraints at spatial infinity. In each case we
evaluate the algebra of conserved diffeomorphism charges following Barnich,
Brandt and Compere, who used a cohomological approach, and Silva, who employed
a covariant-Lagrangian formalism.
  At the Killing horizon, it is only Silva's algebra which acquires a central
charge extension, and which enables us to recover the Bekenstein-Hawking black
hole entropy from the Cardy formula. For the NENH geometry, the extremal black
hole entropy is obtained only when the free parameter of the diffeomorphism
generating vector fields is chosen such that the central terms of the two
algebras are in agreement.
