Check Voltage & Current on MacOS for Power Adapter

Open Terminal.app and type the command:

ioreg -l -n AppleSmartBattery -r |grep AppleRawAdapterDetails

You will get the following information included current and voltage:

“AppleRawAdapterDetails” = ({“IsWireless”=No,“AdapterID”=0,“FamilyCode”=18446744073172697098,“Watts”=89,“Current”=4450,“PMUConfiguration”=4448,“Voltage”=20000})