new battery dies when alarm is armed and will not hold charge after jump for 24 hours alternator has been tested and is okay - the 2nd new battery was fine for months until i set the alarm by mistake

assure the battery negative cable 1/0 battery cable is connected solidly to the chassis ground....wirebrush the spot where it bolts to clean and the lug too...replacing the bolt for a solid 300 cold cranking amps connection~ what can happen is there is a "high resistance" negative connection....making things difficult for the ECU with varying voltages and varying amperages...perhaps even putting itself into a tailspin...which is where we are at right now~