The Blue Sea 7713 does have this behavior. I've done some brief bench testing here, and had a short conversation with Blue Sea tech support. The power for the latching actuation comes from whichever of the main power leads at one of its base terminals is active. Doesn't matter which. Now, even when the latch is released there is a small current draw between the active power lead at the base terminal and ground via the black (ground) wire from the internal controller. So, to completely turn this relay off and remove any parasitic draw while away for extended periods, one must also ensure that the black lead from the 7713 is disconnected from ground. Not having the Chargery BMS in hand (China deliveries from FedEx seem to have fallen into a black hole at the moment) I cannot say if simply unplugging the power lead from the BMS will open this circuit or not. If not, of course, a simple in-line switch should accommodate. It would be friendly if simply unplugging the BMS would also kill any parasitic loads from the 7713. Does anyone using the Chargery know the answer to this? I will follow up when I recieve my BMS and have had a chance to test this feature.