Properties pertaining to thermodynamical local stability of
Reissner-Nordstr\"om black holes surrounded by quintessence as well as
adiabatic invariance, adiabatic charging and a generalized Smarr formula are
discussed. Limits for the entropy, temperature and electric potential ensuring
stability of canonical ensembles are determined by the classical
thermodynamical and Poincar\'e methods. By the latter approach we show that
microcanonical ensembles (isolated black holes) are stable. Two geometrical
approaches lead to determine the same states corresponding to second order
phase transitions.Comment: 25 pages, 11 figures. To appear in JHE