Integrated circuit which acts as a switch
A circuit like this usually works well. The problem is you need current carrying capability, BJT's have a voltage drop and heat up with higher current. A mosfet could be used, like a Pmosfet which is voltage controlled, but the voltage needs to be able to reach the voltage of the mosfet. So you need a switch that works well below 3.3V (BJT) and a mosfet which has a low on resistance for current. 


Source: Part selection for high-side switch