90W USB-C Charger Compatible with Asus Vivobook S 14 - Reliable 90W

In this review the focus is on a single-purpose replacement charger: the 90W USB-C Charger compatible with various Asus Vivobook, Zenbook and ExpertBook models. The bottom line is simple: this is for users who need a compact, USB-C 90W power source that mirrors the output of common Asus 90W adapters and will fast-charge compatible laptops without fuss. The reviewer found it a practical, no-frills substitute for original adapters when the original is lost, damaged, or when a USB-C single-cable solution is preferred for travel.

Key Features

• 90W USB-C output: Delivers up to 90W (20V 4.5A max) so compatible laptops charge at near-original speeds for daily use and moderate workloads.
• Wide input range: Accepts 100-240V 50-60Hz which makes it suitable for international travel without a voltage converter.
• Multiple PD steps: Supports 5V 3A, 9V 3A, 15V 3A and 20V 4.5A to negotiate safe, efficient charging for different devices.
• USB-C connector: Uses a USB Type-C plug which simplifies cabling and works with modern laptops that accept USB-C power delivery.
• Compatibility list: Matches many Asus Vivobook, Zenbook and ExpertBook series models, making it easy to replace ASUS ADP-90RB E or A21-090P2A style adapters.

Who It's For

This charger is aimed at owners of Asus Vivobook S 14, 14X, 16X OLED and similar Zenbook or ExpertBook machines that accept USB-C PD and formerly relied on 90W Asus adapters. It is useful for students, professionals and travelers who need a single charger to power compatible laptops and prefer the convenience of a USB-C lead.

It is not aimed at users needing bundled cables, specialized warranty support from the laptop maker, or those whose device requires a proprietary barrel connector rather than USB-C. If you need OEM certification or bundled manufacturer support, consider sourcing the original adapter from the laptop vendor.

Pros & Cons

Pros

• High 90W output provides near-original charging speed for supported laptops.
• Wide 100-240V input works across power grids for travel convenience.
• Multiple PD voltage steps ensure compatibility and safe negotiation with different devices.
• USB-C connector simplifies cable management and modern laptop compatibility.

Cons

• Aftermarket adapter lacks the official manufacturer branding and bundled support that some buyers prefer.
• Does not include additional ports or integrated cable storage, so it is a straightforward single-port charger.

Specifications

Brand	FLGAN
Connector Type	USB-C
Input	100-240V 50-60Hz
Output	5V 3A / 9V 3A / 15V 3A / 20V 4.5A (90W max)
Compatible Models	Asus Vivobook S/Zenbook/ExpertBook series listed in product details
Replaces	ADP-90RB E / A21-090P2A style 90W adapters

Our Verdict

The 90W USB-C Charger is a sensible, cost-effective replacement for owners of compatible Asus laptops who need reliable USB-C power delivery while traveling or as a spare. Its solid 90W output and wide input range make it versatile, and while it is an aftermarket option without OEM support, it represents good value for anyone prioritizing performance and convenience over branded accessories.

Frequently Asked Questions

Will this charger fast-charge my Vivobook?
Yes, for Vivobook models that accept 90W via USB-C PD the charger negotiates up to 20V 4.5A to provide near-original charging speeds.

Is this safe for international travel?
Yes, the 100-240V 50-60Hz input supports global voltages, but you may need a plug adapter for different wall outlets.

Does it replace the ADP-90RB E or A21-090P2A adapter?
It is compatible with models that used those 90W adapters and is intended as a USB-C alternative to those OEM units.