Check the fuse for how many watts a 12V car outlet can handle.
Generally, a regular 12V car outlet is usually protected by a fuse rated at either 10, 15, or 20 amps. Depending on the fuse, it can handle up to 120, 180, or 240 watts.
I will go into more detail below.
Maximum Power Output
The maximum power output, measured in watts, that a 12V car outlet can handle, depends on the fuse installed on its circuit.
The table below gives the maximum power output for different fuse ratings. Each rating indicates how many watts the Outlet can handle.
Amperage (Fuse Rating) | Maximum Power Output (watts = 12V x DC amps) |
Five amps | 60 watts |
Ten amps | 120 watts |
15 amps | 180 watts |
20 amps | 240 watts |
The Fuse Used in Cars
The fuse used in cars is typically like the one shown below on the left. It will look as shown on the right if it blows out due to power overload.
A fine fuse | A broken fuse |
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Video | U-Haul Trailer Hitches And Towing | Video | U-Haul Trailer Hitches And Towing |
The 12V Car Outlet
The 12V car outlet is also called a cigarette lighter (because it was originally designed for lighting cigarettes) or an auxiliary power outlet.
It usually operates on 12V DC electrical supply from the car battery. However, the voltage is typically elevated to around 13.5 volts or a little more while driving. Also, there is normally only one such Outlet in a car, although some may have more.
Nowadays, various car accessories are available, so it has become necessary to know whether your 12V car outlet can handle them.
Accessories
Now that you know how many watts a 12V car outlet can handle, you might be interested to know what car accessories can or cannot be used in them.
Typical car accessories for use safely are mobile phone chargers, cooling fans, and tire inflators. It may also be possible to use, for example, various USB devices, a portable fridge, a power inverter, or an electric air pump.
Usually, you cannot use high-power appliances on 12V car outlets. For example, you will probably not be able to use a hair dryer or a toaster.
Most car accessories require no more than 120 watts of power. You can safely use them if the specified fuse amperage is ten amps or more. For accessories requiring more than this, check the fuse rating.
FAQs
What would happen if you used an accessory requiring more watts than your 12V car outlet could handle?
In this case, the fuse will blow, and you must replace it and not use the accessory again.
For example, if it’s a 180-watt accessory, you can’t use it if the fuse rating is only ten amps.
Can’t I replace the fuse with a higher-rated one?
You cannot simply replace the fuse with a higher-rated one because the fuse is installed according to how much current the circuit can handle, which depends on the wiring and Outlet.
So, if you want to use a higher-power accessory than the 12V Outlet can handle, you will probably have to replace the wiring with thicker wires.
How can I extend the range of my car’s 12V power outlet?

You can use a portable power outlet like the one in the image.
I have a 24V battery in my truck. Does this mean I can use higher-wattage accessories?
Not necessarily. Although the battery might supply 24V in total, the Outlet is probably 12V. If you’re unsure, consult your truck’s manual.
How many watts do USB car chargers output?
USB car chargers usually output no more than 24 watts, but check the charger to be sure, as this assumes it is rated at no more than two amps.
References
Portable Power Outlet: https://www.dis2buyer.com/?category_id=664205.
Portable Outlet used in Vehicles: https://www.amazon.com/dp/B07NQ6WXPN?tag=nerdcamping-20&linkCode=ogi&th=1&psc=1.
Video References
U-Haul Trailer Hitches And Towing