Can I use 18V adapter for 12V?
18V would be risky, I would not try to plug a 12V device into an 18V battery. But if you happen to have 18V for whatever reason, you can always use a DC-DC converter. I use car-plug type adapters for all my 12v equipment because they have fuses in them.
Can I use a 19v power supply on a 18V?
Yes should be ok just,as you should try and keep to less than 5% difference if possible. Make sure the power output is equal to or greater than the 18V one.Jan 20, 2015
Are all DC power cords the same?
Each AC/DC power adapter is specifically designed to accept a certain AC input (usually the standard output from a 120 V AC outlet in your home) and convert it to a particular DC output. Likewise, each electronic device is specifically designed to accept a certain DC input.
How do I know what size DC plug I need?
Listing of DC coaxial connectors
Connector size is often listed in the format OD (outer diameter) × ID (inner diameter) × L (length of barrel) and expressed in millimeters. Designations may vary between manufacturers. Coaxial plugs that have a male center pin will have another measurement, Center Pin Diameter (CPD).