Modern vehicles have a small but constant battery drain. They are packed full of electrical systems that are constantly working even when the ignition is not running.Alarms, immobilisers, and lock monitoring are examples of systems running in the background that can cause the battery to discharge even when the vehicle is not being used.The OSPOBD is compatible with OSRAM’s OSP500, OSP1000 and OSP2000 Solar Battery Maintainers to allow connection via the vehicles OBDII port for a more efficient connection rather than through the 12V socket.It provides a permanently ‘On’ link between a solar panel and your battery for long term battery maintenance.