  We report on the expected sensitivity of dedicated scintillator-based
detectors at the LHC for elementary particles with charges much smaller than
the electron charge. The dataset provided by a prototype scintillator-based
detector is used to characterise the performance of the detector and provide an
accurate background projection. Detector designs, including a novel slab
detector configuration, are considered for the data taking period of the LHC to
start in 2022 (Run 3) and for the high luminosity LHC. With the Run 3 dataset,
the existence of new particles with masses between 10 MeV and 45 GeV could be
excluded at 95% confidence level for charges between 0.003e and 0.3e, depending
on their mass. With the high luminosity LHC dataset, the expected limits would
reach between 10 MeV and 80 GeV for charges between 0.0018e and 0.3e, depending
on their mass
