When I bought a new 64GB Sandisk UltraFit USB stick and used it, it got very hot, even when it was not used. I compared it to a 32GB Transcend JetFlash USB stick, which didn’t get so hot. So I began to measure the power consumption:
Power consumption according to MacOS:
Sandisk: 896 mA
Transcend: 304 mA
Power consumption according to a Brennerstuhl ammeter by plugging the sticks into a charger and measuring the consumption:
So the power consumption of the Sandisk USB stick is significant higher. E.g. according to these values a powerbank with 6000 mAh would be drained in about seven hours only by powering the USB stick without reading or writing anything. That was a little bit unexpected to me and will reduce the time one can use it with a notebook while running on battery power.