I can not understand why they couldn't have designed or set it up as an option, that when the scanner looses power, such as off ignition source, it can shut down on it's own after a time period. Sure you can set it to run for a specified time, but that is a per use event. After it looses power, it will run off internal battery until they go dead. Obviously, it wasn't a deal breaker, but as always, we the end users will always wish it could do something else than what it was built as. UNLESS, there is a way and I'm just not finding it, if so, somebody please enlighten me. Of course in answer to your situation, I've always been a fan of these for low load items
Bussmann BP/HHH ATM Add-A-Fuse : Amazon.com : Automotive and just wire on a cig plug under the dash to preserve your OEM plug system.