Cell phone specifications now list various fast charging figures. These figures – 10W, 15W, 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.
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How does fast charging work?
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.
For example, you can use a 67W charger for 33W phone without issues; the phone will charge at 33W speeds. Similarly, you can use a 33W charger for 18W phone without issues; the phone will charge at 18W speeds.
18W vs 25W charger
An 18W charger is slightly slower than a 25W charger, so if your smartphone supports 25W fast charge, you really should get a 25W charger for use with it. However, if all you have is an 18W charger, that will work but only charge at 18W speed.
20W vs 25W charger
A 20W charger is slightly slower than a 25W charger, so if your smartphone supports 25W fast charge, you really should get a 25W charger for use with it. However, if all you have is an 20W charger, you might not even notice the difference, because they are really close. I have a 25W fast charge phone and have tested it with a 20W charger and I didn’t notice the difference in charging speed.
33W vs 67W charger
A 67W charger will charge your phone faster than a 33W charger. If your smartphone supports 67W fast charge, you really should get a 67W charger for use with it. However, if all you have is a 33W charger, that will work but only charge it at 33W speed.
How fast does 10W charge?
10W charging is not exactly fast charging. It will charge your smartphone from 0 to 50% in about 30 minutes and take a over 2 hours to get to full power capacity.
How fast does 15W charge?
15W fast charging will take your phone battery from 0 to 60% in about 30 minutes, and then slows down. Time to a full charge is about 2 hours.
How fast does 18W charge?
18W fast charging will take your phone battery from 0 to 80% in about 35 minutes, and then slows down. Time to a full charge is just under 2 hours.
Can I use a 18W charger for a 10W phone?
Yes, you can. However, the phone will charge at 10W charging speed.
How fast is 20W fast charge?
20W fast charging will charge a compatible device from zero to 50% battery strength in 30 minutes.
Can I charge a 10W phone with a 20W charger?
Yes, you can charge a 10W phone with a 20W charger, but note that it will charge at 10W charging speed only.
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 charger?
33W fast charging will charge a compatible device from zero to 60% battery strength in 30 minutes. Personally, 33W is really good. It is the minimum charging speed that I recommend for people who want to be able to top up their phone batteries quickly. 25W charging is close and quite manageable. Call me spoilt, but I find anything lower than 25W or 33W too slow in 2023. If you can get something higher, even better.
Can I use 33W charger for 10W phone?
Yes, you can. But note that the phone will charge at 10W speed.
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.
Fast Charger Prices in the United States
The prices of smartphone fast chargers in the USA can vary depending on the brand, type, and features of the charger. Generally, you can expect to find fast chargers for smartphones ranging from around $15 to $50. However, some high-end models with advanced features can cost more than $50.
You just might be interested our explainer article about fast wireless charging, another on the best Apple iPhone SE chargers available to buy today in the United States of America and Canada, as well as our in-depth guide on fast charging on Android. You will also be interested in how to properly charge your smartphone battery.