Ready to go w/ 2 6v batteries: converter/wire question

bgrasspkr wrote:
looks like I buy a hydrometer tomorrow :)

Do get the glass tube with bobber kind ($10?) and not one of those plastic sideways things that are hard to operate. You don't need the expensive bobber kind that are accurate down to 100 decimal places or whatever that "some guys on here" insist on. The $10 job will be "good enough".