07-22-2019 12:12 PM - edited 07-22-2019 12:14 PM
The battery voltage and power supply voltage have nothing to do with each other. It has integrated voltage regulation modules that convert the voltage to the required voltages to power the device and simultaneously drive the battery. The voltage has to match with what the input is designed for, and that is 20V in the Z710. The amperage can basically be higher than required as the devices request an amperage and use how much they need (for the Z710 type 80AK, there were three power supplies: 20V on each, but with either 3.25, 4.5 or 6.75 Amps for 65, 90 or 130 Watts power output), but a differing voltage (unless your device is made for special fast charging types oder mostly USB Type-C, which most laptops aren't) will most likely fry your motherboard/batteries. By the way, the batteries in your Z710 run at either 14.4 or 14.8 Volts, not 12V.
07-23-2019 12:50 AM
07-23-2019 09:20 AM
Considering that the voltage drops on batteries based on how charged they are, that is not the greatest idea. The effort to keep the voltage in check would be too high for this to make sense.