We analyse the properties of the synchronisation transition in a many-body system consisting of quantum van der Pol oscillators with all-to-all coupling using a self-consistent mean-field method.We find that the synchronised state, which the system can 9x11 pergola access for oscillator couplings above a critical value, is characterised not just by a lower phase uncertainty than the corresponding unsynchronised state, but also a higher number uncertainty.Just below the critical coupling the system can evolve to the unsynchronised steady state via a long-lived transient pomyslnaszycie.com synchronised state.We investigate the way in which this transient state eventually decays and show that the critical scaling of its lifetime is consistent with a simple classical model.