  We study the behaviour of extremal and near-extremal black holes at low
energies and low temperatures and find that it can be understood from the
near-horizon $AdS_2$ region. Our analysis includes charged matter and also goes
beyond the $S$-wave approximation. We find that the leading behaviour at low
energies arises from a mode linked to time reparametrisations and from phase
modes arising from gauge fields. At somewhat higher energies, additional modes
arising from higher partial waves can also be cumulatively significant. These
results can be applied quite generally to cases where an $AdS_2 \times S^d$
near-horizon geometry arises, including black holes in asymptotically $AdS$ and
flat space-times.
