I was looking for battery tray design for my Tdi SL which would allow 4 x 18650 batteries. As luck would have it on the local Prospecting Australia website  XLOOX posted a simple mod for a Whites factory battery tray. I don't know how to post links so the full description is to be found in the Prospecting Australia site. Simple cut out the guts of the tray, leaving the original battery connectors with mods on one end and a copper connector on the other.  I can fit Panasonic NCR18650B cells, with