Andrew, The most common problem that will run the battery down is the door switches. This subject has come up many times, You might want to look in the archives for all the answers. One thing you can do to insure the problem doesn't happen again is put on a battery cut off switch. After all the answers, most resort it the cut off switch. The other thing you may want to do is make sure the battery is fully charged. If it runs down, for what ever reason, allow a battery charger to fully charge the battery over night. I have a small 6 amp that does a great job. I also have the larger types to for the shop but you have to allow the battery to charge fully. If you don't do this, then you will put a major strain on the alternator. John Hervey http://www.specialtauto.com/