Breaker Box for DC Loads
This link indicates that a standard Square D circuit breaker panel with QO breakers works for DC operation at 12 and 24 volts, but not for higher voltages. The same breakers can be used - which are rated for lower voltage than under AC operation.
In pertinent part:
The Square D line of QO breakers and QO load centers are rated for 120/240 Volts AC, and they also have a lower voltage DC rating. When used in DC branch circuits (circuits from the battery to the load) they can be used on 12 and 24 Volt battery systems. Although rated for 48 Volts DC, the higher battery voltages (above 48 Volts) in normal charging and during equalizing pose stresses on these breakers and they should not be used in 48 Volt battery systems.