What you are describing is "high side switching", as opposed to "low side switching" where the switch is between the load and ground. High side switching is generally more difficult because the gate voltage is with respect to the souce pin, and the souce is not at ground. But your control voltage is with respect to ground. So some translation is required. One common solution is to use a P-channel enhancement-mode FET as the switch with the source connected to the battery. Then use a voltage translation circuit (like a PNP transistor) to invert the control signal and translate it so it is also with respect to the battery. Another solution is to use an N-channel enhancement mode FET as the switch and drive the gate with a specialized charge pump gate driver circuit that translates the control signal to be with repect to the FET source. For more information google "high side switching".