  We consider primordial nucleosynthesis in the presence of hypothetical
quasi-stable doubly charged particles. Existence of $X^{--}$ with macroscopic
lifetimes will lead to the formation of its bound states with $^4$He and other
light elements, significantly facilitating the subsequent formation of lithium
nuclei. From observational constraints on maximum allowable amount of lithium,
that we update in this work, we derive strong constraints on the abundance and
lifetime of $X^{--}$. In a likely cosmological freeze-out scenario with
temperatures initially exceeding the mass of $X^{--}$, the BBN constrains the
lifetime of these particles to be less than about 100 seconds. For
parametrically long lifetimes, lithium abundance data constrain $X^{--}$
abundance to be less than $10^{-9}$ relative to protons, regardless of whether
these particles decay or remain stable. Stable particles could saturate the
dark matter density only if their mass is comparable to or in excess of
$10^{10}$ GeV, and most of $X^{--}$ will be found in bound states with
beryllium nuclei, so that chemically they would appear as abnormally heavy
helium isotopes.
