My Pro 3 came with a 12 volt power supply. Long ago, I got a second power supply. After market, also 12 volt. My Surface Book has a 15 volt supply. I have always kept them clearly apart, not knowing what the 15 volts might do to the Pro 3. I am looking for another after market power supply. One with a USB charger, like the original. I see a lot of 15 volt supplies that claim they are for the Pro 3. I have seen some called 15 volt, 24 watt, some 12 volt 44 watt, and some 15 volt 55 watt. Goofy. I guess I could get an OEM charger and not think any more about it, but it is odd to me. Anyone know of a budget minded travel charger to goes well with the Pro 3?