I don't think there is one. The eGO and its cousins are based on the narrower 510 atty. Although the 901 and Kr8 cartomizers (with adapters) would fit, the 801 atty is too fat.
There are rumors of an eGO-like battery for the 801. I believe that Janty shelved its plans for the "Baby J", but I noticed this on
IndyVaporShop's website:
The caption: "
Coming Soon For your 801." Ooo!
BTW, there is now a Riva-like battery for the
Kr8: the 750 mAh
Elegant from CigEasy. Other Kr8 suppliers may follow.