Cosy seems to be working pretty well for me so far. I’ve set my thermostat to be warmer during the two cheap periods, so the house only needs a few short cycles in between.
I’m also charging the battery up during those times, which almost lasts until the next morning:
93% of the electricity I buy is at the cheap rate, and almost none at the peak rate. Average rate is 16.7p (inc VAT).
