According to Redarc, change the battery A connection problem would produce a different error message. Check the battery date, it may still be covere4d by warranty
The guy from Redarc rang me back about this situation
it turns out that if you select Storage instead of Touring in the options and there is a load on the batteries ( in my case the 12 v TV) the batteries will drop and the dry cell detected in output battery signal will come up
As my batteries are new I will check and recharge batteries and reinstall