Welcome, Jana! According to V2's website, they make adapters that will allow you to use other
batteries w/ V2 cartridges, but nothing about using other cartridges on their
batteries. Do you know what kind of threading the GS carts use? If it's not proprietary, you'll probably be able to find an adapter.
(I'm waiting for a chat operator at Greensmoke. Will report back.)
EDIT: Just had a chat w/ GS. Their answer to "what threading do your
batteries use?" was: Sorry, we are not allowed to give out that information. Maybe someone else here can help you. (Frankly, if it were me, I'd steer clear of a company that refuses to give out such basic information, but that's just me...)