Cut to hight of four sr44, silver cell batteries, a paper tube, with several layers, and use some double sided copper contact tape (both sides conduct electricity) about 1/4" or 6mm wide, to connect the batteries to each other (no tape on very top and bottom of the battery pile.
The tube just holds the batteries in line, stacked on each other and is removed once the pile is made.
The double sided adhesive on both sides of the tape holds things in place, but if you need to use single sided copper adhesive, just fold a short hinge between each of them, adhesive between negitive and positive cells in the stack.
Simple and quick to do and a muchbetter electrical contacts than aluminum foil, which some folks use.
Cheers.