looked all weekend to find a device with a 9 volt battery that plugs into lighter to maintain your electronics when you need to pull the main battery. Apparently the computers need up to 200 miles to reprogram themselves if the battery is disconnected / the radio too will need to be coded to work again - this thing gives enought juice to maintain the programs ( apparently they are less than 10 bucks - but so far no one here in San Diego knows where to get one. If you know please email me I'd like to buy one. Thanks in advance..