Does an Extension Cord Affect the Charging Time? (We Checked)

If you use an extension cord to charge your phone, you may be wondering if it affects the charging speed.

The longer the extension cord, the more resistance it has to electricity. This means that less electricity will be able to flow through the cord and reach your device, meaning your phone will take longer to charge than if you used a shorter, more efficient cord.

However, there are some other factors that come into play when considering how long it takes for your phone to charge. In this article, we’ll look at how both of these issues affect charging time and whether or not they should be taken into account when buying an extension cord.

Here’s If an Extension Cord Affects the Charging Time:

If you have a long extension cord, it will affect the charging time. The longer the extension cord, the longer the power takes to travel. That being said a normal extension cable is not long enough to even make a difference or for it to have any eefct on your charger.

Extension electric cable reels isolated on white background

Do Extension Cords Make Charging Slower?

If you’re using a wall outlet to charge your phone and you have the option of using a longer extension cord, the actual amount of time it takes to fully charge your phone won’t be affected that much.

This is because the length of the wire isn’t really a factor when it comes to how much power you can push through it.

If you have a 100-foot extension cord and plug it into an outlet that delivers 1 amp of power, your phone will still take just as long to charge as if you used a 3-foot extension cord plugged into a similar outlet.

However, if you’re trying to use one outlet for multiple devices or appliances at once — such as charging your phone while cooking or watching TV — then an extension cord can cause problems with the electrical system in your home.

The reason has everything to do with voltage drop:

  • To prevent damage from electrical spikes or surges, appliances need consistent levels of electricity throughout their circuits.
  • If voltage drops below what’s needed by an appliance, damage can occur — like blowing out lights or burning out motors in appliances like refrigerators.

Does an Extension Cord Lower the Power Output of Chargers?

A lot of people believe that using an extension cord with a charger or portable battery pack will lower its power output. This is not true.

When you plug in a device, it draws only as much power as it needs from the outlet.

If there’s more than enough capacity, your device gets all of it and if there’s less, it gets some but not all of it.

So no. The power output is not affected by the length of cord used. However, if you’re using a long extension cord to charge your phone in an outlet that’s farther away from the charger, it will take longer to charge because the electricity has further to travel.

The amount of voltage drop depends on the type of cord you use:

  • But it’s usually measured in volts per meter (V/m) or millivolts per foot (mV/ft).
  • A typical smartphone charger has a maximum output of 5V at 1A (5W), so an iPhone 7 Plus charging cable would lose about 0.4V per meter when using a 3-meter cable.
  • For example, if you’re using a 3-meter cable with an 18W charger, your phone would take about twice as long to charge compared to when plugged directly into the wall outlet without any extension cord.

Check out this blog about do extension expire or work permanently? 

Do USB Extension Cables Affect How Fast a Phone Will Charge?

In the quest to find the best way to charge your phone, you might have read up on USB cables and chargers. It’s worth noting that there are two main types of cables: micro-USB and USB Type-C.

The former is the standard for most Android phones, whereas the latter is used by Apple and many other smartphones.

You can still use both types of cables with each other, but you won’t get any benefits from using one over another.

The type of cable that you use has no impact on how fast your phone charges — as long as it supports fast charging (or “quick charging”), which most newer devices do.

In other words, you can use any cable with any charger that supports this feature and it’ll work fine. The only thing that will affect how fast your device charges is whether or not it has quick charging capabilities built-in; if so, then all you have to do is plug it into a compatible charger and wait for it to get fully juiced up.

There are three factors that affect how fast your phone charges:

  • The voltage of the charger (5V for most USB ports and wall chargers)
  • The amperage of the charger (2A or more)
  • The resistance of the circuit between the charger and the phone (the cable).

The problem is that not all devices can support these higher speeds. Some of the older models might not be able to handle them at all — they’ll just fail when you try to use them at super-high speeds.

Others might be able to handle it but only at certain times — maybe when they’re connected directly to a power supply or while they’re running under specific conditions.

And some newer models will fully support them even when they’re connected through an extension cable or adapter dongle.

How to Extend Your Phone’s Charging Time With a Power Bank

Power banks are portable battery packs that can be used to charge your phone or tablet on the go.

They come in a variety of sizes and capacities, but most can extend your phone’s charging time by at least one full charge or more — so long as you have enough juice in them.

Do Extension Cables Damage Chargers Over Time?

There’s no evidence that this is true. In fact, many people prefer to use longer cables because they’re easier to manage around the house and they don’t get tangled as easily as short ones do.

You might have noticed that some chargers come with an extension cable included, but don’t worry — this isn’t because they’re damaged by using another kind of cable.

It’s just easier for the manufacturer to sell one product instead of two separate items that may not be compatible with each other (or even work together).

The longer the cord, the more resistance there is to the flow of electricity. This means that less power makes it to your device but like we said the length needs to be very great for this to affect the phone charger.

If you’re using an extension cord with a charger, be aware that it will take longer to charge your phone than if it were plugged directly into a wall outlet or surge protector.

Do Extension Cords Lose Power the Longer They Are?

No, the length of an extension cord should not affect its ability to transfer electricity. All extension cords are made of copper wire and share a common ground (which is their main weakness).

If you were to cut an extension cord in half and measure the voltage, amperage and resistance with a multimeter, you would find that both cords have exactly the same values. The only difference between them is their length.

The reason why this myth exists is because when you use an extension cord with a device, you will notice that the device takes longer to charge when it’s plugged into an extension cord than when it’s plugged directly into the wall.

This is because your device draws more current from the outlet than it can handle, which causes its voltage regulator to kick in and drop its output voltage.

If you had two devices plugged into each other via extension cords, then they would draw more current from each other than either could handle individually — meaning that if one dropped out due to overloading, then both would drop out at once.


Use a short extension cord to charge your phone and other devices. A short cord will not lose much power and can charge your device quickly.

Use the original charger if possible. It’s better than using an external charger or an adapter because it has more power than other chargers and adapters do.

Read this blog about can extension cords be left outside?


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