I want to use a connector to charge the 4S Battery of my underwater robot. The connector is the 6 Pin hybrid Cobalt Series connectors from BlueTrail Engineering (https://www.bluetrailengineering.com/product-page/cobalt-series-bulkhead-connector).

This connector will provide +Batt and -Batt of the battery as well as the balance connectors of the battery used in this project (https://bluerobotics.com/store/comm-control-power/powersupplies-batteries/battery-li-4s-15-6ah/).

I would like to avoid having the battery tension available on connector's pins during survey (to avoid corrosion on pins, even if I have a watertight lid), but I want to be able to charge the battery (i.e. to have the battery connected to the charging connector) when I want to charge the robot.

To do so, I would like to use if possible the switch used to connect the battery to the circuit when the switch is pushed (through a Mosfet), and which could "connect" the battery to the Cobalt Connector when the switch is released. Here is the switch / Mosfet schematic used to let the battery current flow in the circuit, when the switch put the Mosfet grid to the mass.

I have two questions :

• Is it possible to connect / disconnect the battery from the Cobalt Connector through an electronic circuit ?
• Is it possible to use the general ON/OFF switch such as when the system is not powered, the battery can be charged through the port ?

Many thanks for your help