  The $B_c^\pm$ mass and lifetime measurements using the decay $B_c^\pm \to
J/\psi \pi^\pm$ at the LHCb experiment were studied. About 310 signal events
are expected for a data set which corresponds to an integrated luminosity of 1
fb$^{-1}$, with a $B/S$ ratio equal to 2. Based on these data, the $B_c^\pm$
mass and lifetime can be measured with expected statistical errors below 2
MeV/$c^2$ and 30 fs, respectively.
