The Tesla Roadster actually has two battery systems:
1 - Primary - Used for propulsion consisting of Lithium Ion Cells in a Battery Pack Enclosure.
2 - Secondary - Used to power the 12 Volt DC electronics in the car such as the Navigation System, Audio Equipment, Dash and Headlights, Wiper Motor, Window Mechanism, etc.
The stock secondary battery from Tesla is a 12 Volt 8 Amp hour AGM maintenance-free design, and usually lasts about two years before needing replacement. It is mounted in front of the passenger side wheel well.
GPS has an upgraded secondary battery system conversion also consisting of an AGM battery, with an additional 4 Amp Hour capacity pushing the battery specs to 12 Volt, 12 Amp Hour. Cable adapters are supplied with our product converting the stock terminal cables to an F2 Fast-on tab.