After spending the last hour on this site i will apologize ahead of time for my ignorance, I am humbled by the collective knowledge, if not a little frightened. I want to build a memory saver used when changing out batteries that uses a OBD2 connector. I would like to use a 12v power supply, as most available products do. The problem with existing products that run on 12v is most OBD2 systems have a 5a fuse and if a module or component is on while the memory saver is in use it will blow the fuse. How can I keep the current under 5 amps at all times, while maintaining voltage? Is this even a valid question or am I wasting our time? If the latter is the case, i again apologize. Thanks.