If you get the doohickey from @johan it makes it a lot easier to read your battery voltage - http://www.ecigssa.co.za/threads/whats-a-good-multimeter-to-buy.1420/page-15#post-83433.That's awesome
@Rob Fisher last question for the night... how will I know when my battery needs a swap out?
Most swap batteries at around 3.7/3.8 volts.