I just hope the V4L batteries will work properly with GN's charger, since I got their portable charging case, which I would definently still use if V4L were compatible. GN battery is going to die sooner or later (likely sooner) so I'll have to just use a V4L and hopefully charge it with my GN case, which can take a beating. I need something durable for sure.
I vaguely remember reading somewhere that the GreenCig batteries were reverse polarity... which means that you couldn't and shouldn't use their charger with the V4L batteries.
That's the way that I remember it.. but I certainly could be mistaken. I don't have any Greencig batteries myself.. only their cartomizers (yuck!).