Will a 5V 300mA USB device run safely off of 3 AA Batteries?

I'm trying to make a 5V 300mA USB device portable, but I don't know how to measure/calculate milliamps for anything. What's the mA on 3AA Batteries? Pretty sure the voltage is 3.5, but please correct me if I'm wrong. Basically: if I chop the USB connector off and wire the device to 3 AA's, will the device operate safely, or will it get damaged?

gmxx7 years ago
your device should operate safely.

if you are ok with circuits, you can step up the voltage to use 2 batteries.

https://www.instructables.com/id/Simple-USB-Altoids-AA-Charger/
http://www.adafruit.com/index.php?main_page=product_info&cPath=10&products_id=14
Re-design7 years ago
3 x 1.5 = 4.5 volts. The mA rating is different on diff. types of batteries. The specs on usb rate the voltage from 4.5 to 5.25 approx. I don't remember exactly. So it's at the bottom of the usb spec. 4 batteries would be 6 volts and that would be over the rating and would need some regulation back down to 5 volts. Whether or not it will work depends on the device in question. Very few things would be damaged by too low a voltage so it would be okay to just try it as an experiment. The batteries probably won't last very long but it's an experiment.