Warning about using Duracell PROCELL batteries in your altimeter: I came across a post on FB where people were saying their drogue, main or both weren't firing while using the Duracell PROCELL battery. I had the same trouble while running redundant RRC2 Mini's and using J-TEK E-matches. So I ran 10 tests with E-Matches, what I determined was although the battery was new and at 9.4v it wasn't delivering a strong enough current FAST enough to ignite the E-Match. The RRC2 gives power to the match for a full second but these batteries just can't keep up, once I ran the output diagnostic test on the RRC2 and HELD the Enter button down the E-Match ignited proving it took longer than 1 second to deliver enough power to ignite the match. Once I swapped out the battery with a new Panasonic Alkaline Power Plus battery I ran the manual test again 3 times, however this time when I hit the Enter button in diagnostic mode I hit it as fast as I possibly could and each time the E-Match went off instantaneously! Originally I thought the Duracell PROCELL were supposed to be a quality battery? but after further investigation I was told that these were actually generic Duracell batteries. No these test are not definitive but there enough to make me swap out all my Duracell PROCELL batters. Disclaimer: This wasn't a very scientific test, I by no means am telling anyone what to use, use what you will. These were my findings and is only an informational post.