The wave is giving the following error:

www flickr.com/photos/67725228@N04/6164169668/

(batteries have been discharged more than 90%)

but that is definitely not the issure we have a different wave which we have tested the batteries out with and we have also switched the batteries with a wave that had brand new ones.

What do you think could be the problem? I was thinking that the display (that displays fault codes and battery life)

but we have also replaced that - it was not the problem.