Well, without a suitable capacitor to decouple your +24V rail and absorb the back EMF spikes, depending on the quality of the battery contacts (vibration-caused intermittent open circuits, etc), wire inductance, battery internal resistance, battery capacity to react to transients, etc, your +24V is only pure theory, since during MOSFET switching, it could vary from minus a few hundred to plus a few hundred volts, so yes, anything that sits on it will blow...
What is the motor inductance and maximum current ?