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We present high-resolution VLT/UVES spectroscopy and a detailed analysis ofthe unique Broad Absorption-Line system towards the quasar SDSSJ165252.67+265001.96. This system exhibits low-ionization metal absorptionlines from the ground states and excited energy levels of Fe II and Mn II, andthe meta-stable 2^3S excited state of He I. The extended kinematics of theabsorber encompasses three main clumps with velocity offsets of -5680, -4550,and -1770 km s$^{-1}$ from the quasar emission redshift, $z=0.3509\pm0.0003$,derived from [O II] emission. Each clump shows moderate partial covering of thebackground continuum source, $C_f \approx [0.53; 0.24; 0.81]$. We discuss theexcitation mechanisms at play in the gas, which we use to constrain thedistance of the clouds from the Active Galactic Nucleus (AGN) as well as thedensity, temperature, and typical sizes of the clouds. The number density isfound to be $n_{\rm H} \sim 10^4\rm cm^{-3}$ and the temperature $T_e \sim10^4\rm\,K$, with longitudinal cloudlet sizes of $\gtrsim0.01$ pc. Cloudyphoto-ionization modelling of He I$^{*}$, which is also produced at theinterface between the neutral and ionized phases, assuming the number densitiesderived from Fe II, constrains the ionization parameter to be $\log U \sim -3$.This corresponds to distances of a few 100 pc from the AGN. We discuss theseresults in the more general context of associated absorption-line systems andpropose a connection between FeLoBALs and the recently-identifiedmolecular-rich intrinsic absorbers. Studies of significant samples of FeLoBALs,even though rare per se, will soon be possible thanks to large dedicatedsurveys paired with high-resolution spectroscopic follow-ups.

Low-ionization iron-rich Broad Absorption-Line Quasar SDSS J1652+2650: Physical conditions in the ejected gas from excited FeII and metastable HeI