wrote on Apr 4^th, 2011 at 11:55pm:

IMO it is much easier to remove a battery cable.

Anyone who wants to do this could be helped by this little tip. BEFORE you disconnect the negative battery cable connect a 9 volt battery between the negative and positive cables - heed the polarity. Leave the 9 volt battery connected while the ground cable is disconnected and while you are on your trip. This will preserve all of the electronic memory in modern cars. Things like radio presets and fuel injector air/fuel ratio etc. I don't know for sure if the nine volt can make it as long as a month but it would be worth a try. This is a good tip to use anytime you want to do work on your car and need (should) disconnect the battery.

You could also use an 8 AA battery pack rather than a 9 volt battery. I've used both with good results. I suspect the 8AA's would last considerably longer.