I bought http://www.amazon.com/Griffin-Techno...178282-1679670
which works to charge the Vox, only the software doesn't recognise it's being charged. You need to press the reset button inside the back panel in order to reset the software battery monitor.
I've often plugged my Vox in, using the 3rd party charger linked above, with about 20% battery left prior to bed, read/surfed for an hour, then left it to charge in standby all night. In the morning, pressed the reset button and the battery status was 100% and properly followed the discharge during the day.
Many discussions about 3rd party chargers here ----> https://www.mobileread.com/forums/sho...37#post1807137
and here ----> https://getsatisfaction.com/kobo/topics/charger_for_vox
Cheers and good luck.