porterhouse; this system basically replaces two different systems that would present the same hurdles as the factory systems, if the batt. goes dead. First, you would have to gain access via the standard door key, then open the hood and recharge the battery. The reader's memory is non-volatile so all the codes should still be intact upon wake-up. I would also suggest that you try never to 'jumpstart' on any car. jumpstarting spins the starter and energizes the ignition and fuel stuff, but as soon as the engine lights-off, the alternator is charging into effectively a near dead short - the dead battery. If that is the only option then let the charging vehicle run hooked up to the dead car for a few minutes before trying the dead car. Still bad, but maybe survivable by both. Xfire1a; now I hope I don't lose my extra key and have a dead battery at the same time!! I'm fully capable of doing that.