Regarding the car lowering voltage during charging from 40amp to 30 amp in the middle of the night. Per Jerry33 (whom I can't quote because of his sig), I have manually set the amps to 38 for the last three months. I've had zero instances of auto amperage drop in that time. So for anyone experiencing that 25% drop, I think this is a great solution. Sure you don't get that extra 2 amps, but you also don't get the unpleasant surprise that your car isn't done charging in the morning.