Do you need a fast charger for your phone?

In today's fast-paced world, being able to top up your phone battery in a pinch is a great convenience. But are fast chargers all they're hyped up to be?

With help from our mobile phones expert, we explain how they work and whether it's worth investing in one.

Plus, find out if fast chargers can damage a battery, why you should shop carefully for phone adapters online, and see our pick of the best models. 

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How does a fast charger work?

In simple terms, a fast charger works by sending a greater number of watts (W) to your phone, increasing the speed at which the battery charges – the higher the wattage, the quicker the charge. Charging capacity for modern phones can vary quite dramatically, and you'll need the right adapter to make the most of it.

While terminology varies depending on the brand, generally speaking 'slow' or 'standard' charging refers to phones that have 5-10W charge capacities. 'Fast charging' phones can charge at around 25W, and anything faster than around 40W is usually called 'super fast charging'. There are also a few brands, like Oppo and OnePlus, who offer even faster charging, in some cases upwards of 100W.

In order to buy an adapter that'll make the most of a phone's charging capabilities, you'll need to know your phone's charging capacity, and make sure any adapter matches or exceeds it. 

Do you need a specialised cable for fast charging?

Not all USB-C cables support fast charging, so if you're using one that's been knocking around in a drawer at home you may be wasting a charger's potential. Things to look out for on suitable cables are the USB-PD standard (this stands for Power Delivery, and is typically capable of handling higher wattages), cables listed with a specific wattage rating, such as 60W, or that use terms such as 'fast charging'. 

If you're using a cable that's supplied with a phone, google around to see if you can find out the wattage that cable supports. For example, a search for 'samsung 24+ supplied cable wattage' reveals that the cable supplied with the Samsung Galaxy S24+ supports 25W charging. That's fast enough for 'fast charging', but not enough for 'super fast charging', which requires a cable with a capacity of 45W (plus a fast enough charger).

Hate running out of juice? Our portable power bank charger reviews reveal the top models to keep your devices running.

How effective is fast charging?

In our tests we found that using a fast charger can make a big difference. For example, a 15 minute charge of the iPhone 14 with a normal 5W charge got us to just 10% battery. With a 20W fast charger, it reached 31% in the same time frame. A fast charger also cut charging time in half when going from a flat to full battery, down to one hour and 45 minutes from three hours and 15 minutes.

At the extreme end of the scale, the Xiaomi 12 Pro is capable of a whopping 120W maximum charge capacity, and this powered the battery to 71% after 15 minutes, with a full charge taking just 25 minutes. Compare that to the Motorola Moto G62's 10W charge capacity limiting it to 11% in 15 minutes, and two hours and 45 minutes for a full charge.

Amy Axworthy, Which? mobile phones expert says:

'A fast charger can significantly increase the charge time of your phone, but consider whether it's really worth the expense of buying a super-fast charger – 20-25W is probably about the sweet spot.

'If you do go higher,  buying a charger that's 'too fast' does somewhat future-proof the purchase, and you may be able to use it to charge other devices, like tablets and laptops, depending on their charging capabilities. Since phones and other devices limit the charge they can take in, there's no danger of damaging a device, but higher wattage chargers are more expensive.'

Is fast charging bad for your battery?

There are various 'good hygiene' measures that claim to help a battery last longer. These include not leaving a phone on charge once it's full (by, for example, aiming to keep the battery level between 20% and 80%) and not letting your phone overheat (which can degrade your battery at a faster rate).

A fast charger can make these rules more difficult to follow, but in truth, they're unlikely to have a serious impact on battery health, provided you pick a good quality charger.

Most modern phones include measures to help prevent unnecessary battery strain, such as 'learning' your routines so charge can be distributed more evenly when you're not using a phone (for example when you're asleep), or stopping the charging process when a phone reaches 100%, and topping it up again once it has dropped. Head to the battery settings on your phone to see what options are available.

If you do find your battery degrading over time, replacing it and keeping the phone can be very cost effective. Read more in our guide to mobile phone repair. 

Why you should shop carefully for phone chargers online

Phone chargers can be pricey, especially manufacturer-brand models from the likes of Apple and Samsung. If you've ever shopped for these on an online marketplace though, you'll see hundreds of attractively priced alternatives that could seem too good to pass up.

However, non-official chargers can be dangerous. In the past, we've found counterfeit plugs, leads and adapters from online stores like Wish, eBay and AliExpress that failed our safety tests and standard electrical strength tests. We've also consistently found issues with unbranded electronics bought from online marketplaces. So avoid these, and any seemingly branded chargers that appear too cheap to be genuine – using these dodgy appliances could cause electric shock or excessive overheating of your phone. In worst cases, your phone can actually explode, or the charger can catch fire.

Fortunately there are trustworthy alternatives to the big-brand chargers – see our recommendations below.

Make sure you know your rights when shopping on online marketplaces, and how to get a refund, repair or replacement on a faulty product before you shop.

Best fast chargers for iPhones and Android phones

You can buy fast chargers from a range of different retailers - we've listed options from trustworthy brands below. You may have to buy the plug and lead separately. 

20W chargers

Apple's USB-C power adapter is designed to work with a range of Apple products and has foldable pins.

Or consider this Belkin charger as a cheaper option – with the same 20W output.

30W chargers

For phones with higher charging capacities, this model from URGreen, which offers a wide range of adapters, is a compact and solid option that's great for travel, with collapsible prongs.

Anker is another reliable brand, with this 30W charger also coming with a USB-C to USB-C cable included. You can buy it in black or white.

45W+ chargers

URGreen and Anker also have a range of faster chargers for phones and other devices. This model from Anker comes with an 18-month warranty. Anker says it's 'designed for Samsung, but compatible with a wide range of devices including iPhone, iPad, and much more'.

Should you buy a wireless charger instead?

Wireless charging is a popular alternative that avoids that awkward process of having to actually plug a phone in - here you just put it down, and watch it go. Wireless chargers work by using a charging pad to send an electric current through your phone, charging up the battery. Not all phones currently support it, so make sure you check to see if yours is compatible.

While many find it a more convenient method, it is generally a slower way to charge than wired charging. Many phones also won't be able to absorb as much power wirelessly as they will when plugged in. For example, the Apple iPhone 14 can charge up to 15W via a wireless charger (the same amount as an Apple MagSafe charger emits), but can charge up to 20W wired.

Due to the slower speeds, wireless chargers are popular for places where you're likely to leave your phone idle for a while – beside your bed, or at your desk, so they can get a convenient top up when not in use.

How to recycle your old phone charger

The most straightforward way to recycle your old chargers is to drop them off at a recycling centre or local tip. Most will have a bin specifically for cables, cords and electrical products.

Alternatively, retailers like Currys offer a recycling scheme. Simply bring your old chargers to your local Currys store and they'll recycle them for free, regardless if you initially bought them from Currys or elsewhere. Apple also has a recycling scheme for Apple products only. Head to any Apple store with your old lead, plug or cable to have them recycled free-of-charge.

Get rid of your tech responsibly - find out how to recycle your mobile phone and how to recycle your laptop