As freshandminty's post.
Or back in the day I used to fit one of these.
![](http://173.203.80.233/media/listings/image2/2011/01/Battery_Cut_Off__4c4030a96e1c6.jpg)
Stick it between the battery -ve and the earth cable that bolts to it. Cheap as chips.
You might need to get a bit more clever if you want your clock to remember the time, or your radio to remember stations![:)](//storage.proboards.com/forum/images/smiley/smiley.png)
But kill either the ignition circuit or the starter with it and you've produced an obstacle for some thieving barsteward.
Or back in the day I used to fit one of these.
![](http://173.203.80.233/media/listings/image2/2011/01/Battery_Cut_Off__4c4030a96e1c6.jpg)
Stick it between the battery -ve and the earth cable that bolts to it. Cheap as chips.
You might need to get a bit more clever if you want your clock to remember the time, or your radio to remember stations
![:)](http://storage.proboards.com/forum/images/smiley/smiley.png)
But kill either the ignition circuit or the starter with it and you've produced an obstacle for some thieving barsteward.