A charger fits your phone, yet the familiar fast-charging message disappears. The problem may be compatibility rather than a faulty battery. USB-C describes the connector. Charging speed also depends on the protocol, the electronic conversation between phone and charger, and on what the cable can carry. A higher wattage printed on the adapter cannot settle those questions by itself. USB-IF explains power negotiation.
USB PD, PPS and Quick Charge: what the names mean
USB Power Delivery, usually shortened to USB PD, lets compatible devices agree on the power supplied. A compliant, higher-powered PD charger does not force its full output into a smaller phone. The phone requests what it supports. USB PD can reach 240W with suitable equipment, but that is the standard's ceiling, not a promise for every USB-C socket. USB-IF's PD guide sets out these capabilities.
PPS means Programmable Power Supply, a feature within USB PD that lets the phone request finer voltage adjustments as charging progresses. Both ends must support it. Look for an explicit PPS specification, including its voltage and current range. Samsung's 45W adapter, for example, specifies PD 3.0 PDO/PPS and includes a 5A cable. A generic PD label alone does not establish equivalent support. USB-IF's PPS guidance explains the compatibility requirement.
Qualcomm Quick Charge is another charging family. Check the phone's supported version and the accessory's certification. Qualcomm now lists Quick Charge 5+, with backward compatibility. Its Quick Charge 5 announcement also documents USB-PD support. That does not make an older Quick Charge adapter interchangeable with every modern PPS charger.
Why another brand's charger can be slower
OPPO and OnePlus use SUPERVOOC, vivo uses FlashCharge and Xiaomi uses HyperCharge. Their fastest modes depend on the supported combination of phone, adapter and cable. OnePlus explicitly recommends its matching SUPERVOOC adapter and cable. Vivo's Y27 specifications tie 44W FlashCharge to an 11V/4A standard adapter. Check the exact model's requirements before substituting accessories.
UFCS, the Universal Fast Charging Specification, aims to make fast charging work across brands. The Fast Charging Alliance describes it as a shared protocol developed with Chinese industry participants including Huawei, OPPO, vivo and Xiaomi. It is a separate compatibility item to look for. Do not infer UFCS support on an Indian model from the brand name or a Chinese model's specification.
Two products can share a USB-C connector but lack a shared high-power mode. OPPO's support guidance specifically identifies protocol differences as a reason another brand's charger may be slower. Even a matching setup varies during a session: charging generally slows near full, while heat and demanding apps can reduce speed. See Xiaomi's charging explanation and Apple's charging guidance.
Read the small print on the adapter and cable
Read the adapter's Output ratings. Watts equal volts multiplied by amps: 9V at 3A is 27W; 20V at 3.25A is 65W. Separate voltage options are alternative operating modes, so do not add them together. A multiport charger's headline total may also be shared between devices. Check its simultaneous-output table. USB-IF's technical guide covers fixed outputs and power allocation.
For standard USB-C to USB-C charging above 3A, use a 5A cable with an e-marker, a chip that identifies the cable's capabilities. A 3A cable reaches 60W at 20V. Some phone charging modes need more than 3A even below 60W, so wattage alone is insufficient. USB-IF's cable specification documents electronic marking.
USB-IF's current certification programme requires USB-C to USB-C cables to show 60W or 240W power markings. For USB PD above 100W, choose the appropriate 240W Extended Power Range cable. Proprietary high-current cables still need the phone maker's compatibility check. For laptops, confirm USB PD charging support and the recommended adapter wattage; Apple gives that advice for Macs.
Qi and Qi2: wireless has compatibility limits too
Qi is the Wireless Power Consortium's wireless-charging standard. Qi2 uses magnetic alignment to position the charging coils properly. The original Qi2 offered 15W; WPC announced Qi2 25W on 23 July 2025. A magnetic attachment alone does not prove certification or a particular charging speed. Match the phone, charging pad and required power adapter, checking each product's specifications. WPC's Qi overview and 25W announcement explain the standards.
India's USB-C policy and the BIS safety check
India's common-port initiative has specific official milestones. On 16 November 2022, Consumer Affairs reported stakeholder consensus on USB-C for smartphones, tablets and laptops, with a phased rollout envisaged. BIS's 5 January 2023 press note announced IS/IEC 62680-1-3:2022, covering USB-C ports, plugs and cables. Consumer Affairs publicised it through PIB on 9 January 2023. These documents establish the standard and policy direction, not a dated, blanket sales mandate. A common connector also does not guarantee identical fast-charging speeds. Sources: Consumer Affairs meeting release, BIS press note, PIB announcement.
For safety, look for the BIS registration mark and R-number on the charger, then check that number against the product details. Power adapters for IT equipment fall under the Compulsory Registration Scheme. The BIS Care app provides a verification facility. Registration addresses conformity with the applicable standard; it does not establish that a charger supports your phone's fastest protocol.
Which charger should you buy?
First check the box contents. Samsung says it omits chargers to reduce duplicate accessories and electronic waste, encouraging owners to reuse existing equipment. Reusing a suitable adapter can avoid another purchase. Include any necessary charger and cable in your budget, alongside the questions in our earbuds versus phone upgrade guide.
Three official India store examples illustrate the choices:
- Apple 20W USB-C Power Adapter: Rs 2,190, listed MRP including taxes. Charging cable sold separately.
price as of 9 October 2026, 12:53 IST, checked on the official Apple India store.
- OnePlus SUPERVOOC 80W Power Adapter, White: Rs 1,899, displayed selling price. Match it to the phone and required cable.
price as of 9 October 2026, 12:53 IST, checked on the official OnePlus India store.
- Xiaomi 120W HyperCharge Adapter Combo, White: Rs 2,299, displayed selling price. The listing specifies an included 6A cable.
price as of 9 October 2026, 12:53 IST, checked on the official Xiaomi India store.
For sharing between compatible phones and a laptop, start with USB PD, add PPS where required, and check each port's output. For a proprietary phone's maximum speed, buy its documented compatible combination. If packing a power bank too, consult our separate power bank flight rules guide.
