2009 Infiniti G37 battery failed, now key fob issue

Hello,
I have a 2009 Infiniti G37 that seemed to have had an issue with the battery.  
Driving along and all the lights went out, headlights, dash, etc.  But still ran.  
Tried to get home and finally the engine died.  Let it sit for a couple of hours,
came back with another car, let battery charge for several minutes and
jumped off.  Ran fine all the way home.  Battery was 5 years so replaced
with new one and cleaned corroded battery terminals (think that was my
main problem).  Alternator seems to be charging, 14.5V while running.  Been
running fine for two weeks now, but ever since then the car will not start
unless the key fob is inserted.  Before I could just keep it in my pocket.  I've
tried both key fobs and same thing.  What reads the key fob proximity?  Is
that something I can troubleshoot?  Or am I destined for a trip to the
dealership?
Thank you.