PD Charging 101: What Is USB-C Power Delivery and How It Works

If you've seen the term PD charging on a charger or cable and wondered what it means, you're not alone. PD stands for Power Delivery — a fast-charging standard that delivers higher levels of power over a USB-C connection. In simple terms, PD chargers help smartphones, tablets, laptops, and other devices charge faster and more efficiently than traditional USB chargers. 

In this guide, we’ll explain what PD charging is, how it works, what “PD” means on a charger, and how to know if your devices are compatible. 

What is USB-C Power Delivery, and how does it work?

The latest USB Power Delivery (USB-C PD) version 3.1 was released in 2021. It lets us quickly charge larger capacity batteries than we were able to in the past, supporting up to 240W. 

A USB-C PD Charger can detect the device it’s connected to. If that device supports the PD protocol, it will negotiate/communicate with the charger and send the appropriate amount of power to provide the fastest possible charge.

Here’s how the PD charging works in practice:

Power negotiation between the device and the charger

This negotiation happens automatically in milliseconds, following strict safety rules defined by the USB Power Delivery standard:

• The charger advertises the power levels it can provide
• The device evaluates which options are safe and supported
• The device requests the specific power level it requires
• The charger confirms the request before increasing output
• Power delivery begins only after both sides agree on the limits

To put this into context, consider a 100-watt USB-C PD charger used with different devices. A smartphone such as an iPhone 14 will typically draw only 20–27 watts, even though significantly more power is available.

A 14-inch MacBook Pro, by contrast, may request 67 watts or more depending on battery state and workload. In each case, the charger delivers only the amount of power requested — no more, no less — ensuring efficient and safe charging across devices.

What happens if you plug in both a phone and a laptop into a multi-port PD charger?

When multiple devices connect to a 100-watt, multi-port USB-C PD charger, each negotiates power independently.

If total demand exceeds capacity, the charger intelligently reallocates output, temporarily slowing charging to maintain safe, stable power delivery.

Charging phases and battery protection

USB-C Power Delivery is designed to deliver fast charging when a battery is low, then gradually slow output to protect long-term battery health. As the battery fills, charging speed is intentionally reduced to minimize heat and limit wear on internal components.

The charging curve typically looks like this:

• 0–50%: Fast charging at the highest safe wattage, typically reached within about 30 minutes
• 50–80%: Moderated charging as the battery nears capacity, usually taking an additional 20–30 minutes
• 80–100%: Slow, tightly controlled charging to protect battery chemistry, often taking as long as the earlier stages combined

PD Charging voltage, amps, and watts explained

To understand how USB-C Power Delivery works, it helps to look at the three core measurements used to control charging:

• Voltage (V) describes the force that pushes power toward a device. USB-C PD commonly operates at 5V, 9V, 12V, 15V, or 20V.
• Amperage (A) measures how much electrical current flows at a given moment. Many PD chargers support up to 5A.
• Wattage (W) represents total charging power and is calculated by multiplying voltage by amperage. Modern PD chargers typically deliver between 15W and 100W.

Here are common voltage and amperage combinations used by PD chargers.

These voltage-and-amperage combinations define the maximum power a charger can make available, which is why higher-wattage chargers can safely power smaller devices. The device — not the charger — controls both the voltage it receives and the current it draws.

For example, a phone may negotiate 9V at up to 2A, or roughly 18W, even when connected to a 100W charger capable of delivering 20V at 5A. The charger simply adjusts to the requested voltage and supplies only that amount.

Is PD the same as USB-C?

USB-C refers only to the physical connector and cable design, not how power or data is managed. Power Delivery (PD) is a separate protocol that operates over a USB-C connection, enabling higher and adjustable power levels.

Because USB-C supports multiple standards, a charger may use the same connector yet deliver only basic 5V charging

PD vs Quick Charge (QC): What’s the difference?

Short answer: the USB PD charging protocol supports a broader range of devices and delivers higher power levels than Quick Charge (QC).

Here’s the comparison of PD and QC standards commonly available on the market.

USB Power Delivery (USB-PD) was built as a universal charging standard capable of powering phones, tablets, and laptops across manufacturers.

A key differentiator is support for Programmable Power Supply (PPS). It allows the phone charger voltage and current to adjust dynamically in small, continuous increments, in contrast to jumping between fixed levels such as 5V or 9V.

This feature enables devices to fine-tune power as the battery fills, reducing heat buildup and protecting battery health.

Quick Charge (QC), by contrast, originated as a fast-charging solution for Android smartphones using Snapdragon processors. Earlier QC versions lacked PPS-style control.

Beginning with QC 4.0, however, QC chargers and compatible devices rely on USB Power Delivery with PPS to achieve comparable charging performance.

This makes PD 3.0/3.1 PPS and QC 4.0/5 very similar in how they work, with the only distinction that PD 3.1 delivers more wattage.

What devices support PD charging?

USB Power Delivery is now supported across most modern device categories:

• Smartphones. Apple introduced PD with the iPhone 8 in 2017, and every iPhone since supports it. On Android, PD has become the default standard on devices such as the Samsung Galaxy S20 series (2020+), the Google Pixel 6 (2021+), and newer flagship models from OnePlus and Xiaomi.
• Tablets and Chromebooks. Devices including iPad Pro (2018+), iPad Air (2020+), and most Chromebook models released after 2019 support USB-PD.
• USB-C laptops. Most modern laptops now rely on PD, including MacBook Air (2018 and newer), Dell XPS, HP Spectre, and Lenovo ThinkPad systems.

Note: Non-PD chargers remain safe to use with PD-compatible devices but result in noticeably slower charge times.

Why PD charging matters in shared and managed environments

USB-C Power Delivery offers clear advantages over older Quick Charge standards and non-PD adapters:

• A single PD charger can power most modern phones, tablets, Chromebooks, and laptops
• Many smartphones can reach up to 50% charge in 30 minutes or less when using PD
• Intelligent power negotiation and PPS reduce heat and help extend battery lifespan
• A standardized USB-C PD ecosystem simplifies charger management and reduces the need for replacements

These benefits make PD charging especially valuable when devices are used continuously, must recharge quickly and reliably, and users need the flexibility to swap chargers. This is exactly what happens daily in schools, healthcare settings, IT departments, and shared business environments.

PD-compatible charging solutions by LocknCharge

Not all charging stations are created equal — especially when it comes to USB-C PD (Power Delivery). If your organization relies on fast-charging mobile devices like iPads, Chromebooks, or USB-C laptops, choosing a PD-compatible charging station is essential for minimizing downtime and maximizing device availability.

Below, we’ve listed the best LocknCharge charging stations and smart lockers that support USB-C PD charging, with options tailored for everything from classrooms and healthcare to IT-managed enterprise fleets. Whether you need compact portability or full remote locker access, there’s a solution built for your workflow.

iQ 10 Charging Station with USB-C PD

The iQ 10 Charging Station with USB-C PD is a compact, wall- or desk-mounted unit designed for schools and businesses needing a secure place to store and charge multiple USB-C devices. With built-in USB-C PD charging, it can charge up to 10 iPads, tablets, or other USB-C-enabled devices simultaneously. Its compact footprint and lockable front door make it ideal for classrooms, labs, or shared workspaces where space is tight but secure charging is essential.

✅ Best for: iPads, tablets, and small-form USB-C devices in space-constrained environments

CarryOn Charging Station with USB-C PD

The CarryOn is LocknCharge’s most portable charging station — a lightweight, briefcase-style solution that securely stores and charges 5 USB-C devices using USB-C PD. Built for mobility, it's perfect for scenarios where educators, IT staff, or frontline workers need to transport charged devices between locations. Devices stay protected during transit and charge while stored, making the CarryOn a go-to for flexible deployments.

✅ Best for: Mobile device deployments in schools, healthcare, or hybrid teams needing grab-and-go convenience

Putnam Charging Station with USB-C PD

The Putnam Charging Station supports USB-C PD charging for 8 or 16 individual devices, with each bay featuring a dedicated USB-C port and charging indicator light. The vertical, stackable design allows it to be scaled across rooms or buildings without eating up floor space. With PIN-code access and a tamper-proof build, the Putnam station ensures that devices stay secure, charged, and accessible to the right users.

✅ Best for: Schools and organizations needing secure, easy-to-manage device check-in/check-out workflows

FUYL Smart Charging Locker

The FUYL Smart Charging Locker is LocknCharge’s most advanced solution, combining cloud-based device management with USB-C PD charging in each of its 5, 8, 15 or 23 individually lockable bays. It allows IT teams to deploy, track, and recover devices without needing to be on site — supporting workflows like self-service loaners, broken device swaps, and off-hours checkouts.

Each bay includes both an AC outlet and a USB-C PD port, so devices can charge securely even while unattended. IT teams have full visibility and control through the FUYL Portal.

✅ Best for: IT-managed device fleets in education, enterprise, healthcare, and public service

Looking for PD-compatible charging solutions for schools or teams?

LocknCharge offers scalable charging stations that keep your USB-C devices secure, powered, and ready to use — with support for Power Delivery protocols.

Talk to a specialist

FAQs

Are Lightning devices PD compatible?

Lightning devices like the iPhone 12, iPhone X and various iPads have been PD compatible for some time. Using a PD charger in conjunction with an MFI-certified Type-C to Lightning cable allows for higher current draw and faster charging.

What happens if my device doesn’t support PD protocol, but I plug it into a PD charger?

If the attached device does not support the PD protocol, communication cannot be established. By default, a lower charge rate is used. The short of this being that it may just take longer to charge than normal.

Is PD charging safe for phones, tablets, and laptops?

Yes — USB Power Delivery is safe because the device controls the voltage and current it receives, preventing overcharging or overheating.

CanI charge a PD device with a QC charger?

PD devices will charge safely from a Quick Charge (QC) charger, and will fast-charge if the QC charger supports USB Power Delivery, as is the case with QC 4.0 and newer.

Can I fast-charge a QC phone with a PD charger?

Phones that support QC 4.0 or newer can fast-charge from standard USB-C PD chargers.

How do I know if my phone supports PD charging?

Check the phone’s packaging and specifications. “USB Power Delivery,” “PD,” or “PD PPS” in the charging or battery section. If it’s listed, the phone supports PD.

How to know which phone chargers support power delivery?

Check the charger’s specifications, printed either on the packaging or on the product itself. If the charger’s specifications say 18W, it most likely supports Power Delivery.