Using a adapter with 7.5 DC volts and 1000 ma will probably not power the easy start, but you can use it to charge your 7.2 battery (nicad). If your battery is dead then plug it in for about 2 hours or until the battery gets slightly warm. The battery is full charged when warm. This may get you by until you find a charger.

Also dropping the voltage from the car battery to 8 volts or less will power the easy start directly . I just don't know how to do it.