Best Power Bank for ASUS ROG Ally: Wattage and PD Needs
Updated 2026-07-20 · Power Bank Guide
Why the ASUS ROG Ally Needs a Dedicated Power Bank
The ROG Ally is a high‑performance handheld PC that draws between 20‑30 W while gaming and up to 40 W for heavy multitasking. A power bank that can deliver 20 W or more over USB‑C Power Delivery (PD) will keep the Ally running during long travel or outdoor sessions. If you also use tablets, earbuds, or a Steam Deck, a 22.5 W bank is a sweet spot for most devices.
USB‑C PD Wattage Explained
USB‑C PD specifies the maximum power a charger can supply: W = V × I. A 20 W bank can output 5 V × 4 A, 9 V × 2.22 A, or 15 V × 1.33 A. A 22.5 W bank typically offers 5 V × 4 A or 15 V × 1.5 A. The ROG Ally’s charger is 20 W, so a 22.5 W bank gives a small headroom for voltage fluctuations and ensures steady delivery.
Real‑World Charging Numbers for 20,000 mAh / 74 Wh Banks
Watt‑hours are calculated as mAh × 3.7 V ÷ 1000. A 20,000 mAh pack equals about 74 Wh, which is under the 100‑Wh limit for most airlines (check your carrier). Efficiency losses (usually 60‑70%) mean you get roughly 50‑55 Wh usable. That translates to:
- iPhone 17 (~10 Wh per charge): 5–6 full charges
- Samsung Galaxy S24 (~11 Wh): 4–5 charges
- Steam Deck (~12 Wh): 3–4 charges
- ROG Ally (~18 Wh per hour of moderate use): 2–3 hours of continuous play
Choosing the Best Power Bank for ROG Ally and Other Gadgets
When shopping, look for:
- USB‑C PD 20‑25 W output
- At least 20,000 mAh capacity
- Dual ports or a single high‑power port if you only need the Ally
- Flight‑safe design (≤100 Wh) and included USB‑C cable for convenience
- Compact size for travel or backpack use
What 22.5 W Can and Can’t Run
With 22.5 W you can:
- Charge the ROG Ally for a couple of hours of gaming
- Top‑up an iPad Pro or iPad Air in a single session
- Charge a Nintendo Switch in under 10 minutes (fast‑charge mode)
- Power a pair of earbuds or a DSLR camera for extended use
- Fully charge a full‑size laptop that needs 45‑60 W
- Charge a high‑end gaming console like the PS5 or Xbox Series X
- Deliver 100 % efficiency; expect 60‑70% usable output
Final Recommendation
If you need a versatile, flight‑safe power bank that covers the ROG Ally, tablets, Switch, Steam Deck, and everyday gadgets, the INIU 20000mAh Portable Charger is an excellent choice. Its 22.5 W output, ample capacity, and compact design make it the best power bank for ROG Ally and other portable devices.
FAQ
Can I use a 20 W power bank to charge the ROG Ally?
Yes, a 20 W bank will charge the Ally, but it will be at the lower end of the device’s power envelope. A 22.5 W bank offers a little extra headroom for stable charging.
Is a 20,000 mAh bank safe to carry on a plane?
It is under the typical 100‑Wh limit, but always confirm with your airline’s latest regulations before traveling.
How many times can I charge my iPhone with this bank?
About 5–6 full charges, assuming 60‑70% real‑world efficiency and a 10‑Wh battery.