We combine complementary datasets to constrain dark energy .
Using standard Big Bang Nucleosynthesis and the observed abundances of primordial nuclides to put constraints on \Omega _ { Q } at temperatures near T \sim 1 MeV , we find the strong constraint \Omega _ { Q } ( \mbox { MeV } ) < 0.045 at 2 \sigma c.l..
Under the assumption of flatness , using results from Cosmic Microwave Background ( CMB ) anisotropy measurements , high redshift supernovae ( SN-Ia ) observations and data from local cluster abundances we put a new constraint on the equation of state parameter w _ { Q } < -0.85 at 68 \% c.l..