There are actually a couple of vendors selling Vgo replacement batteries, which are pretty much the same as the INFERNO standard 900mAh battery.
At the current time, the INFERNO 650 mAh USB PT battery appears to be a Volcano exclusive item, as far as I have been able to determine.

https://www.breezesmokes.com/index.php?option=com_tienda&view=products&task=view&id=201&filter_category=12&Itemid=68

http://revolvercig.com/accessories#tsvgocart

Google turned up one other site, but that site seems to be offline at the current time, with a message that there are unresolved site issues that are being worked on.

The above listed vendors also carry replacement/spare cones and chargers as well.

One thing worth pointing out is that the INFERNO PVs, and their component parts, like all other Volcano products (except atomizers & cartomizers) do come with a 1 year warranty, so the first option for a replacement would be a warranty one, since the INFERNO hasn't been on the market anywhere near a year yet.

Yeah the 650 bat is the one I like the most...what a work horse...does the 900 vgo have usb pt too??
or would I be better off just buying an ego kit next time???

So far as I have been able to find out, only Volcano has the USB PT models in the Inferno/Vgo style.

They are widely available in the eGo style however.

The difference between the two essentially is that the eGo uses a screw on type of atomizer cone, while the Vgo uses a push on type of atomizer cone.

Well Thanks for the loads of info Dave...your a cool dude!!!! LOVE the Avi By the way!!!!!