  We present spectroscopic and photometric solutions for three spotted systems
with red giant components. Absolute physical and orbital parameters for these
double-lined detached eclipsing binary stars are presented for the first time.
These were derived from the V-, and I-band ASAS and WASP photometry, and new
radial velocities calculated from high quality optical spectra we obtained with
a wide range of spectrographs and using the two-dimensional cross-correlation
technique (TODCOR). All of the investigated systems (ASAS J184949-1518.7, BQ
Aqr, and V1207 Cen) show the differential evolutionary phase of their
components consisting of a main sequence star or a subgiant and a red giant,
and thus constitute very informative objects in terms of testing stellar
evolution models. Additionally, the systems show significant chromospheric
activity of both components. They can be also classified as classical RS
CVn-type stars. Besides the standard analysis of radial velocities and
photometry, we applied spectral disentangling to obtain separate spectra for
both components of each analysed system which allowed for a more detailed
spectroscopic study. We also compared the properties of red giant stars in
binaries that show spots, with those that do not, and found that the activity
phenomenon is substantially suppressed for stars with Rossby number higher than
$\sim$1 and radii larger than $\sim$20 R$_\odot$.
