Your phone is at 12%, the cable has vanished, and somehow that tiny charging pad now looks like the smartest thing on your desk. 

So, how does wireless charging work without a plug in your phone? The answer comes down to a magnetic field, two coils, and a compatible device that knows how to receive power. It feels almost effortless, but not every phone, charger, or charging speed works the same way. 

Qi compatibility, wattage, alignment and case thickness can all affect the result. Here is what you need to know before you choose a wireless charger for everyday use.

How Does Wireless Charging Work?

Wireless charging works through electromagnetic induction, a process that transfers energy between two closely positioned coils. This wireless charging technology does not send electricity across a room. Your phone normally needs to sit directly on, or just millimetres above, the charger for efficient power transfer.

Electricity first reaches the pad through its cable and power adapter. An alternating current passes through a transmitter coil inside the charger and produces a changing magnetic field. 

A receiver coil inside your phone detects that field and generates voltage, which the phone converts into usable electrical power for its battery. Traditional Qi systems typically operate between 87 and 205kHz.

Alignment makes a measurable difference. The Wireless Power Consortium states that coupling is strongest when the two coils line up closely and the distance between them stays small. Poor placement, a thick case or a foreign object can reduce the amount of power that reaches the phone. 

Our Wooden Wireless Charging Pad With Phone Holder shows how this works in practice. It supports 5W, 10W and 15W Qi charging, while the built-in holder keeps the phone in a consistent position over the charging area. Even with a 15W model, the phone still controls how much power it accepts based on its own charging limit. 

What Is Qi Wireless Charging?

Qi, pronounced “chee,” is the global wireless charging standard managed by the Wireless Power Consortium. It first appeared in 2010, and more than 13,000 Qi Certified products now exist across phones, chargers and other portable devices. 

The standard matters because certified products from different manufacturers can work together instead of relying on a brand-specific charger.

There is an important difference between Qi Certified and labels such as “Qi compatible” or “works with Qi”. A certified product must pass independent laboratory tests for interoperability, safety and energy efficiency and receive a WPC certification ID.

A useful real-world example is our Odyssey Wireless Charging Power Bank. It has a 10,000mAh battery and delivers 5W wireless charging to Qi-enabled devices, so recipients can charge a compatible phone without plugging a cable into the handset. It can also charge two devices at the same time, which makes Qi useful beyond fixed desk pads. 

Qi2 arrived in 2023 with magnetic alignment and charging up to 15W. The magnets position the transmitter and receiver coils more accurately, which helps reduce wasted energy. Qi2 25W launched in July 2025 and raised certified power transfer to 25W, nearly 70% more power than the original Qi2 tier. 

On supported hardware, WPC says it can take a smartphone battery from 0% to 50% in about 30 minutes. A 15W charger is not automatically Qi2; it must specifically meet the Qi2 standard and certification requirements.

How Do You Know If Your Phone Supports Wireless Charging?

Before you buy a charger or order 100 branded units for a team, check the phone's official specifications for Qi wireless charging support. A Qi-enabled phone can usually charge on a compatible Qi pad from another brand because Qi provides a shared standard for power transfer.

A few checks make compatibility much easier:

• Apple: Qi support starts with the iPhone 8 and iPhone X generation. Apple states that an iPhone 8 or later can use Qi-certified chargers, although the maximum wireless charging speed differs by model and charger type.
• Android: Support varies significantly between brands and models. Do not assume a new Android phone includes wireless charging simply because it has a premium specification.
• Phone cases: Thin, non-metallic cases usually cause fewer issues. Thick cases, wallet cases, metal plates and accessories between the coils can interfere with power transfer or prevent a connection.
• Magnetic alignment: MagSafe or Qi2 magnets help position compatible devices correctly, but basic Qi compatibility does not require magnets.

For bulk corporate gifts, check the likely device mix before you choose one charger.

How Fast Is Wireless Charging?

Wireless charging speed can range from 5W to 25W or more on specific systems, but the number printed on the charger is only its maximum supported output. Your phone will not automatically accept all of that power.

For example, Apple's iPhone 15 Pro Max supports 7.5W through standard Qi, 15W through Qi2 and 15W through MagSafe. The same phone can therefore charge at very different rates depending on the charger.

A 15W wireless charger does not guarantee 15W charging. If the phone accepts only 7.5W through that standard, it stays at the lower rate. 

The power adapter matters too, and heat, poor alignment or heavy phone use can reduce speed further. Apple specifically notes that low-power adapters, demanding apps and higher device temperatures can slow a wireless charge.

What Affects Wireless Charging Speed?

A charger’s advertised wattage is its maximum output, not a guaranteed speed for every phone. Real charging performance depends on several factors:

• Phone input: A phone limited to 7.5W cannot accept 15W through the same charging standard.
• Charger and adapter: Both must supply enough power to reach the stated output.
• Coil alignment: Poor positioning increases energy loss and can slow the charge.
• Case thickness: Thick cases, metal plates and wallet attachments can interfere with power transfer.
• Heat and battery level: Phones often reduce power when temperatures rise or the battery nears full charge.
• Phone use: Games, navigation and video calls consume power during charging.

For example, our Soft Wood Cork Foldable Wireless Charger comes in 5W, 10W and 15W options. A 15W version still cannot force 15W into a phone that only accepts 7.5W. For branded gifts, device compatibility matters more than choosing the highest wattage number.

Conclusion

So, how does wireless charging work in practical terms? A compatible charger uses electromagnetic induction to transfer power across a very short distance, while standards such as Qi and Qi2 help phones and chargers work safely together. 

Charging speed still depends on the phone, charger output, power adapter, alignment and temperature, so the biggest wattage figure is not always the best choice.

For staff gifts, client packs or event merchandise, choose a charger that suits the devices your recipients actually use. Explore our range of wireless chargers and branded technology gifts to find practical options for your next New Zealand campaign.

Frequently Asked Questions

Does wireless charging work with every phone?

No. A phone needs built-in support for Qi or another compatible wireless charging standard. Apple has supported Qi since the iPhone 8 generation, while Android support depends on the exact brand and model.

Does wireless charging work through a phone case?

Usually, yes, if the case is relatively thin and does not contain metal. Thick cases, magnetic accessories, wallet attachments and metal plates can reduce efficiency or stop charging completely.

Is 15W wireless charging faster than 5W?

Yes, but only when the phone and charger both support the higher output. A 15W charger cannot force 15W into a phone capped at 7.5W for that charging method.

Is Qi the same as MagSafe?

No. Qi is an industry-wide wireless charging standard, while MagSafe is Apple's magnetic charging and accessory system. Qi2 also introduced magnetic alignment, but the two names should not be treated as interchangeable.

Is wireless charging slower than cable charging?

It often can be, especially with older 5W or 7.5W Qi chargers. Newer 15W and 25W wireless systems have reduced the gap, but cable charging can still provide higher peak power on many phones.