I'd take the PRAM battery out... I mean it only holds trivial settings... Then there is no fear about you forgetting it in there.. the same for your original Mac... I leave them out of all my machines.. And I also take out batteries out of laptops when I store them. I also use a label maker and put on the back with a re-cap date, and specs and I put "NO PRAM BATT".... just how I do it...