Bartholomew, originally an Arab name, became popular in the Christian world as one of the 12 apostles went by that name. 'Bar' in Aramaic means son of, so Bartholomew means son of Talmai.
There are many spellings of Battin such as the more prevalent Batten. The earliest record of the name was Walter Batun recorded in the Feet of Fines of Essex in 1248. There was also Joel Batin recorded in the Hundred Rolls in Devonshire in 1273.
"Batten down the hatches" is a nautical term, probably from the 18th century. A Batten is a strip of wood used for many purposes. In this context, it is used to hold down canvas sheets to cover hatchways in storms.
Battin is a slang verb in Trinidad and Tobago to through your head back to chug down your entire drink in one attempt.