DC power supply for 30A motor driver
They typical way to handle this it to have a resistor bank that gets switched across the input when the voltage rises beyond some threshold.  This absorbs the regenerative energy and dissipates it as heat.

If you can quantify the maximum regen energy you will see in your application you might be able to use a capacitor bank on the input to absorb/reuse the energy.  But you have to size the capacitors so that the maximum energy doesn't exceed the maximum input voltage (or the rated voltage of the capacitors.) 

The battery in parallel with the supply could result in overcharging, so I would not recommend it.