Per the manufacturer it should not burn the pump. An alternator puts out 12 Volts, battery is a 12 Volt battery, Delavan 5850-201 Electric Pump is a 12 Volt pump you will be fine. Be sure there is an in-line fuse for your pump at the battery. It should be a 30 amp fuse.
We have checked with the manufacturer of the Delavan 5850-201 Electric Pump and they stated that it cannot be used with gasoline at all as this could essentially create a bomb if the gas were to get into the pump itself.