Yay!
The new USB Killer V3, which costs about £50/$50, is apparently 1.5 times more powerful than its predecessor, is more lethal (it pumps out eight to 12 surges per second), and is itself more resistant to setups that might cause the USB Killer to fry itself.
A spokesperson clarified this last point to Ars:
"The V3 is engineered to withstand short-circuit configurations, intentional or otherwise. Typically, when a host device fails, it will either fail to an open circuit, or a closed circuit. If a short-circuit isn't detected, the USB Kill would essentially continue to discharge into itself, i.e. suicide."
Since we last reported on the USB Killer, it seems the Hong Kong-based company has also secured FCC approval in addition to the European CE mark. This essentially means the USB stick is human-safe and won't electrocute you.