I was curious to see the loss rates, hence used a 45m and 15m 2.5mm² multi-strand extension cord. I do have a bit of 6mm² T+E so could make a lower loss ext lead, however the 20amp UK ring main it's fed from is based on a 2.5mm² Twin and earth ring not a 32amp 6mm² radial.
In the end the Zappi...