what about this http://www.commonsenserc.com/product...roducts_id=196

Lipo Shield automatically detects the number of lithium cells in your battery pack at power-up and sets the appropriate cutoff voltage. It then continuously displays the detected number of cells by blinking the “Cells” LED. LipoShield works whether you’re running a BEC built into your ESC, a separate BEC such as ParkBEC or even a receiver pack.

still allows the BEC off of the ESC to run, but it can't power anything since it disconnects it, so it would lower the amp draw considerably, probably even into the micro amps, of course depending on the esc

check here for the install guide
http://www.dimensionengineering.com/...LipoShield.pdf