When Dennis Douglas built N9103D, he installed a two-battery electric system to provide backup electrical power for the original Blue Mountain instrument panel. Subsequently the two batteries were replaced with the powerful Odyssey ER30, which is the only battery powering N9103D. Wiring for the original dual battery electric system remains intact and operational with merely replacement of the ER30. An EXP Bus 2 with solid state circuit breakers protects the aircraft’s wiring.