I recently purchased an Emergency Jump Starter, the kind that connects directly to the battery and frame (I know how to jump start a car safely). I check it with the "test" button monthly, but would really like to be sure it'll work for me when I need it.

Can I just take it to a mechanic, and ask them to hook it up to some kind of tester?

I am NOT a "car guy" kind of guy, and appreciate the help.