The following is a graph of the KW load while charging an Energi battery that has been completely emptied. The graph doesn't start and end at zero because this is the total load of my house. Subtract 0.9 KW from the graph to get the charge load. The charge consumed 7.09 KWH. At my rate of $0.16 per KWH that is $1.13. After 1 hour the charge stopped momentarily probably to check the battery state of charge. At the end of the charge cycle the charge rate was stepped down. The charge time was 2:09 with the temperature at 70 degrees.