On the second thought, I am not sure I agree with my previous "additional" loss due to slower charging. 2% input V drop = 2% output W drop = 2% output I drop = 2% less AH over 5.5 daily hours. So it all boils down to daily AH or WH loss, which is equal to input V drop. This is - assuming that bulk mode goes all the 5.5 hours, so in reality there will be less than 2% daily AH loss.
There is of course an additional loss of V,I,W - whatever - from controller to battery, which is a different matter, and a different wire gauge.