After my battery died I found that the Welcab seat wouldn't work. A quick search on You tube gave me most of the answer. After resetting you have to move the seat fully forward and backwards to relearn the positions.
The full procedure is:
Press and hold UP and FORWARD for 15 seconds. BEEP
Press UP 4 times
Press FORWARD 4 times. BEEP
Move seat fully FORWARDS and BACKWARDS to learn travel end-stops.
All functions should be restored.
This worked for my 2010 Vellfire with Welcab front passenger seat.
Hope it helps.