...Yes, the lighter socket CAN supply enough power, but if you're running it for a long time that socket is going to end up being a fire hazard....
Have you heard the term 'voltage drop'? It in part refers to the lowering of available voltage when the wire size is insufficient to support the power demands. Lighter sockets/power outlets in today's cars simply are not wired with heavy enough wire to power even a fifty watt rig when transmitting. Sure, on receive and when transmitting at low power, that connection may--may
--be sufficient, but don't bet on it because of the real weak link in the connection--the socket and plug. Most rinky-dink plugs made today can't even pass five amps without melting!
If you're going to connect a rig in that way, get a quality, heavy duty plug. BTW, even most of the good, heavy duty plugs are rated ten amps maximum, and you have to really look to find those. You really should look at a picture of a car that has been damaged by using cigarette lighter plugs and sockets to power rigs--K0BGs website has those pictures, and most of the time, the center of the damage is the cigarette lighter plug/power socket!
...Why not run the correct size wire from the Battery to the radio in the first place once and for all?
An electrical repair in a vehicle can be very costly.
Very good advice! Too bad some people won't pay attention to the simple basics anymore--if they ever did. 73!