Here is a link to the TSB : Knowledgebase - 2009 G37 Coupe - Infinitihelp.com Forums
"2008-2009 INFINITI G37 COUPE; BATTERY LOW VOLTAGE / NO START
An Applied Vehicle has a Battery Low Voltage or no start condition due to specific customer use pattern

 

Thanks... but it does not apply to Convertibles.

 

I don't think there's too many differences between the 2 models, in particular the EVAP valve and the battery are most likely the same.
I noticed in the past that a TSB for a coupe is applicable to the Vert, for example I had a noticeable clicking from the rear axle which was fixed on warranty as a result of a TSB I waived at the service guy

 

Actually I haven't had any issue with my 09 vert but I'll ask the service adviser when I take my car for service end of this month. Thanks