How To Connect An Extension Cord To A Car Battery?

You may have faced different kinds of problems with your car battery. But, have you ever faced a problem when your car battery died and wondered whether you might get a jump start using an extension cord?

Yes, you can do that! You can use an extension cord in this kind of situation. However, to jump your car battery using AC power, it should be transformed to DC power. Then decreased the power to the right charging range to avoid a huge overcharge that would kill your battery and very likely result in a fire or explosion.

Read the full article to learn the procedure in detailed.

Can We Wire an Extension Cord to A Car Battery?

Yes! An extension cord may be connected to a car battery but not directly to an outlet. Because the battery is 12 volts and the outlet is 120 or 220 volts. The extension cord, on the other hand, may be used to connect the batteries to additional low-voltage items.

However, you can only run a 12V “something” if the extension cord is only linked to the car battery with the jumper wires. Normally, this is done with a cigarette lighter and an appropriate adaptor. A vacuum cleaner, a tiny fan, or a phone charger are common examples. 

However, if you’re going to “plug” the gadget into the extension cable, then that’s the sort of plug it has. Just keep in mind that the car can only produce 12 volts, so anything less or more than that won’t work.

How To Connect an Extension Cord To A Car Battery?

Connecting the extension cord to a car battery is not very difficult but you should be cautious.

There are steps you need to follow to connect an extension to a car battery:

Step 1: Make sure everything is ready and clean

Step 2: Connect the jumper cables with the extension cord. 

Step 3: Attach the extension cord to the battery terminals. First, connect the positive end and then the negative end.

Step 4: Use inverters or DC appliances to the opposite end of the cable and power the battery.

Caution: You can’t connect the battery to anything you like. Let’s have a look at what they are-

  • Never connect the battery to the AC outlets directly. The AC outlets have a voltage of 120 volts. When you attempt to do so, the battery may rupture. If you wish to connect the battery to a wall outlet, you’ll need an adaptor. As a result, the 120 volts is lowered to 12 volts DC.
  • The battery should not be connected to any AC appliances. First and foremost, the battery is merely a 12 V DC power source. The AC appliances have a 120 V AC rating. Hence, connecting the battery to them will provide no results.
  • Do not expose the battery to a short circuit. The current rating of car batteries is excellent. Things will deteriorate if the terminals are shorted. There’s always the possibility of a fire or explosion. Bear that in mind when you connect the jumpers to the terminals.
  • When charging, never connect the battery to a considerably higher voltage source. DC batteries are quite delicate. The battery begins to heat when the supplied voltage is somewhat greater than 12V. Consider what may happen if the voltage is increased!
Extension cord safety tips for plugging in your vehicle

What Are The Characteristics Of A Car Battery?

If we want to understand the nature of the cord and battery, and how you can use it you should know the characteristics of a car battery. 

Batteries in automobiles are DC sources. It includes two terminals, one positive and the other negative. The following are the two primary properties of DC batteries:

  • Rated Voltage (V)
  • Rated Ampere-Hour (AH)

Voltage: A automobile battery’s rated voltage is merely 12 Volts DC. The voltage surges as a source of pressure or energy, causing current to flow across the route. We can’t link a battery to an AC source or perhaps an appliance that works on Ac supply since it’s a DC source.

Another essential property is the ampere-hour. It shows the amount of current a battery can produce for how long. It’s the result of multiplying Ampere with Hour.

Assume that a battery’s Ampere Hour rating is 6AH. It indicates that if it needs to deliver 6 Amperes constantly for an hour, it can do so.

If it has to deliver 3 Amperes constantly for 2 hours, it can do so. As a result, the Ampere Hour represents a battery’s current capacity and standby time.

When Can You Wire an Extension Cord to A Car Battery?

We can primarily utilize it with 12V DC appliances such as DC fans and LED lights. If necessary, we may plug the battery into the inverter with an extension cord.

The inverter is responsible for converting DC to AC. Then we’ll be able to utilize it for air conditioners.

You may also link the battery with a charger with an extension cable.

Therefore, to charge the battery, the charger produces a bit more than 12V. It can be observed that a supply of roughly 16 V heats the battery.

As a result, pay attention to the voltage you provide to the battery.

How To Select Jumper Cables?

You will need a jumper cable to connect the extension cord with the car. Thus, you need to know which one should you pick.

In the marketplace, there are several kinds of jumper cables available, each with its own set of characteristics, current handling ability, and length.

In this part, I’ll highlight the ones that can assist you in making a better jumper cable selection.

The length of the wires. When feasible, use longer jumper cords. They can readily restart a car even if it is parked more than 15 feet away from the automobile with a strong battery.

Jumper cables are available in a variety of lengths, including 10, 16, 20, 25, and 30 feet. Small automobiles can fit in 16 feet, pickup trucks can fit in 20 feet, and light trucks can fit in 30 feet.

Aluminum vs. Copper jumper cable

Jumper cables should preferably be constructed of copper because of their low electrical resistance; however, copper-clad aluminum is becoming increasingly popular. It is less expensive and has received positive feedback.

An Additional feature set

Is your set of jumper cables equipped with characteristics like reverse polarity indicator, which alerts the user if the wires are connected incorrectly? Is there a battery tester with your set of jumpers? Get jumpers that have these characteristics whenever feasible!


Finally, Car batteries can be wired to low-voltage electronics at the exact voltage as the battery’s rated voltage. Therefore, wiring an extension cable is perfectly alright, however, you must be cautious about what you connect to the battery via the connection. It’s a straightforward procedure. Give it a shot at any time. But always be cautious and stay safe.

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