I have a 2011 Nissan Note1.6 Tekna and the spare key has stopped working. I suspect it's just a dead battery but I read somewhere that you only have a limited amount of time to replace it or the key loses it's programming! Does anybody know what type/size of cell it takes. The key is the kind of squarish variety which I assume just splits open to access the battery compartment but plese let me know!