Wow! I'm amazed that the Tesla onboard charger is that inefficient. Anyway, we are not using Teslas, we are using Nissan Leafs. And, we are using DC charging. O

Wow! I'm amazed that the Tesla onboard charger is that inefficient. Anyway, we are not using Teslas, we are using Nissan Leafs. And, we are using DC charging. Our (single phase) inverter is >95% efficient making the round-trip >90% efficient. It is possible that there are some battery losses that are neglected in the calculation, but it is about right. Regardless, even 80% efficiency is comparable to pumped hydro, so I am not sure that 80% efficiency would be damning.