That sounds like the starter solinoid is Not passing enough current to the starter..
Assuming the battery is able to supply the needed Amperage...
I would first check All the cable connections... BOTH Ends of Each battery cable, positive And negative cable.
They may seem tight, but a little build up of corrosion on the cable ends is what will cause the chatter sound you are experiencing... Remove, clean and reattach the cables. Post back with the results. :smile:KennyV