Best phone chargers and cables in NZ: what wattage you actually need

For most iPhones, a USB-C charger rated at 20 W or more that supports USB Power Delivery (USB-PD) gives full fast-charging speed. Apple's fast-charge page lists an 18 W or greater USB-C adaptor, or a comparable third-party USB-PD adaptor, for iPhone 8 and later; the iPhone 17e and iPhone Air reach 50 per cent in about 30 minutes on 20 W or more, and the iPhone 17, 17 Pro and 17 Pro Max use 40 W or more for their fastest charge.

Android phones vary much more. Some use USB-PD, some add their own fast-charging system, and the top speed differs from model to model. Check the charging section of your phone's spec page, then buy a charger that meets that number with the same standard.

Watts are volts multiplied by amps. A basic USB-A port supplies 5 volts, so it can only go so fast. USB Power Delivery lets the phone and charger agree on a higher voltage when both support it. The USB Implementers Forum, which writes the USB standards, says the current version of USB-PD can deliver up to 240 W over a full-featured USB-C cable; earlier versions topped out at 100 W.

The important part: with USB-PD the phone asks for what it can take and the charger supplies that. A 60 W charger on a phone that takes 20 W charges at the phone's speed. A bigger charger only helps if you also want to charge a tablet or laptop from it.

• USB-C Power Delivery (USB-PD): the USB standard. It is what iPhones use for wired fast charging, and many Android phones, tablets and laptops use it too.
• Qualcomm Quick Charge (QC): found on many Android phones. A QC charger will still charge an iPhone, just not at USB-PD fast-charge speed.
• Plain USB-A: fine for overnight charging, earbuds, smartwatches, speakers and older phones. Do not expect fast charging from it.

Multi-port chargers often print the total output across every port. If two phones share a charger, each one gets a slice. Check the per-port figure on the box or product page before you count on it.

The cable has to match both ends and carry the power you want. For iPhone 15 and later, Apple says a USB-C cable such as the one in the box is all you need. For earlier iPhones, fast charging needs a USB-C to Lightning cable; a USB-A to Lightning cable still charges, but at the slower USB-A speed.

USB-C to USB-C cables are sold by the power they carry. A cable rated at 60 W is plenty for any phone and most tablets. According to the USB Implementers Forum, 100 W charging uses USB-C cables rated at 5 amps, and 240 W needs cables built to the newer 240 W requirements, so only pay for those if you are charging a laptop that draws that much.

Micro-USB is still around on older phones, speakers and accessories, and a spare is handy to keep in a drawer. Length is a practical choice: about 1 metre suits a bedside table or car, while 2 to 3 metres reaches from a wall socket to the couch. Browse our charging cables by connector type.

A car charger plugs into the 12 V socket and works the same way as a wall charger. For an iPhone, look for a USB-C port with USB-PD at 20 W or more if you want fast charging on the road. Dual USB-A car chargers are a budget way to keep two phones topped up on long drives, and a Quick Charge port suits Android phones that support it. See our car chargers.

Wireless pads still need a capable wall adaptor behind them. Apple says MagSafe fast charging on iPhone 16 and later needs a 30 W or greater USB-PD adaptor, and iPhone 15 and earlier charge at up to 15 W on MagSafe with a 20 W or greater adaptor. A weak adaptor behind a good pad is the most common reason wireless charging feels slow.

• Buy from a seller you can contact if something goes wrong. In New Zealand the Consumer Guarantees Act says products must be of acceptable quality, fit for purpose and match their description, including when you buy online.
• Retire cables with frayed ends, exposed wire or bent plugs.
• Charge on a hard surface rather than under a pillow. Apple notes that fast charging may not work when it is too hot or too cold.
• Read the output label. It should show volts, amps or watts for each port.

Heading away? Our travel power bank guide covers airline rules, and the earbuds guide covers what to look for in budget audio.