[radhaz]

I highly doubt this is it, but when I had my first car I put in a new battery it ran fine for a few days then one day I got in my car and closed the door and all the accessories died. I popped the hood checked the cable and noticed it was a bit loose, tightened it up and all was well. Then a few days later the problem came back, the remedy was to tighten the ever living snot out of the terminal connectors......

One more thing, if your battery is "sparking" when you connect the leads to it, then you have an accessory that is drawing current ie a light on or something shorted to ground. You mentioned an alarm being installed and most likely that's the reason you are sparking but it is something to look into.

Good luck