Can anyone explain this for me. When the battery is approaching the latter stages of its discharge, it sometimes, well quite often, completely cuts out, and will usually go again with a tap to the pump box. Everything seems connected, so it's not like a spark has to jump across anywhere, was wondering if the switch was a tad sticky, but don't think it is. It's starting to annoy me now cos I had to pack in an hour early cos it wouldn't get going again, but lo and behold it's fine now I'm home!