From what I see the calculation in the OpenEVSE firmware for energy may be doing a simple current times voltage calculation which results in kVAh instead of kWh. I recently noted my OpenEVSE showed 6.44 kWhs and my Sense monitor only showed 5.466 kWhs for a charging session on my Chevy Bolt. The Sense monitor appears accurate as it compares to my utility revenue meter. I am thinking that instead of 6.44 kWhs my OpenEVSE may be reporting 6.44 kVAhs and would be a 0.85 power factor. I cannot locate anything that tells me what power factor the Chevy Bolt AC-DC charger operates at. Does anyone know how the OpenEVSE firmware is actually calculating the energy used as well as what the Bolt charger power factor is?