current rating of automobile cigarette lighter plugs

[W8JX]

If you mean less voltage sags is your free lunch, then yes. But that won't make your cigarette lighter wiring not catch on fire from too high average current.

And just how many cars have had the lighter wiring catch fire?? Maybe if you bypassed fuse and shorted it out.

[NO9E]

We all ( Myself included ) should be very thoughtful of what we print here on the forum.

Good that young people do not follow us blindly.

Excessive safety is sometimes more harmful than normal behavior. Usually devices contain enough safeguards not to be destroyed before a fuse pops up. If they do, perhaps our experience is worth more than the damage.

W8JI has a story about people trying to treat 3-500z lightly. Then, the tube is not gettered enough self-destroys.  

Fairy tale below.

One guy wanted a really strong antenna. He used very heavy wire.  Then 1) a lightning stroke and destroyed his shack, or 2) copperweld wire rusted and "improved" operating bandwidth while reducing the efficiency by 50%, or 3)  very heavy attachments to trees destroyed the trees, and the wire while being removed kinked causing injury, requiring a trip to the emergency room.  

Another guy used a thin tire. He tolerated 2% drop in efficiency compared to a thicker wire. After 5 years, 1) lightning vaporized his wire causing no damage to the shack, or 2) the wire was broken in heavy winds but the tree has survived; he discarded the wire and invested $10 in new wire.

[N4CR]

If you mean less voltage sags is your free lunch, then yes. But that won't make your cigarette lighter wiring not catch on fire from too high average current.

And just how many cars have had the lighter wiring catch fire?? Maybe if you bypassed fuse and shorted it out.

It's a metaphor.

[KM3F]

Fuse values in cars and truck are engineered to fail long before wire overheats unless some fool put in higher capacity fuses.
He then deserves to get what he gets from doing so.
No mfger would want the liability of losing a vehicle in the owners hands from a proven over fused circuit as part of it's normal speced design.
Trucks often are designed and wired for a bit larger current.
In a Ford F150, The Cigar lighter is fused at 20 amps. It's socket is not the same as  a standard power port.
The power port along side of it, is also rated at 20 amps.
In these trucks there are two fuse panels. One in the engine bay and one in the dash.
Normally power port appliance plugs are not rated above 10 amps and very often have their own fuse inside the plug at no more than 10 amps if that..
One must look at the power port rating for fuse size in any vehicle to be sure before using it for other than a normal appliance use.
Good luck.

[W7HBP]

Anyone have any idea how much current you can draw from the cigarette lighter plug in most automobiles? I want to push ~ 400 watts mobile but not sure if this is too much current draw.

Lane
Ku7i

Most are on a 15 amp circuit. But the wire is so small to the acc socket anymore, I suspect 7.5 amps. Some have a thermal protector in them too. If its overloaded, this thermal protector will open and shut the circuit down. Here is what I'd do and did. As a Toyota dealer tech, I liked the idea of the switch socket. But I ran a power source right to a terminal block, full 12V using 12AWG wire right from the battery with a 15A auto fuse right near the power rource. Then at after the terminal block, I installed a Bosch type relay to turn the power on and off using the cigarette lighter socket to power up the relay only, no radio load on the small acc socket circuit.