# Fast Charging Explained: How fast is 18W, 20W, 25W, 33W, 44W, 67W, etc?

Cell phone specifications now list various fast charging figures. These figures 18W, 20W, 25W, 33W, 44W, 67W, 120W, 180W, etc. are power output values. They represent how much power the charger or power adapter in question is capable of delivering to the phone or tablet it is plugged into. The higher the power output figure, the faster the charger is capable of charging. Standard charging is a measly 5W. So, a 10W charger is faster than a 5W charger. An 18W charger is faster than both.

Note that when it comes to fast charge, the rating of both the power adapter and the device are important. If you plug a 33W charger to a phone that supports only 10W charging, it will deliver only a 10W charge to that phone. A device will not charge faster than it is capable of, no matter what kind of fast charger or power adapter you use with it.

The principle is that more power or current output will charge a battery faster. The higher the output, the faster the charging. Note, however, that the charger and the phone will work only at a mutual rate. When you plug in a phone to charge, the power adapter and the phone have a quick conversation to decide on a mutual voltage and a maximum current that may be drawn by the phone. This maximum current is dependent on the kind of charging standard or technology built into the phone.

By default, the decided power output or current is whatever standard the slower device is. If the power adapter has a lower rating, the maximum current drawn will be restricted to that. If the phone has a lower charging rating, the maximum current drawn will be limited to that. Today’s charging bricks come with intelligent chips that help make this mutual understanding possible. So, using a higher rated charger will not likely damage your phone.

## How fast is 20W fast charge?

20W fast charging will charge a compatible device from zero to 50% battery strength in 30 minutes.

## How fast is 25W fast charge?

25W fast charging will charge a compatible device from zero to about 50% battery strength in 30 minutes.

## How fast is 33W fast charge?

33W fast charging will charge a compatible device from zero to 60% battery strength in 30 minutes.

## How fast is 44W fast charge?

44W fast charging will charge a compatible device from zero to 70% battery strength in 30 minutes.

## How fast is 67W fast charge?

67W fast charging will charge a compatible device from zero to 50% battery strength in 15 minutes.

## How fast is 120W fast charge?

120W fast charging will charge a compatible device from zero to 100% battery strength in 19 minutes.

## How fast is 180W fast charge?

180W fast charging will charge a compatible device from zero to 100% battery strength in 17 minutes.

Note that all of the above charging times are approximates. The actual charging times may vary slightly depending on the implementation of each manufacturer. New, faster charging technologies and standards are being introduced all the time, so expect faster and faster standards, till we have instant charging. With instant charging, your phone will go from zero to 100% in a flash.

## Can you use a non-fast charging power bank or power adapter for a phone that is normally charged with fast charging?

Oh, yes; you can use a non-fast power adapter or power bank with a fast charging phone. What will happen if you do that is that the phone will charge at regular 5W charging speed. That means it will likely take up to 3 hours from zero.