For most users, a 20–30W power bank handles phones fast, while 45–65W covers tablets and light laptops.
If you’re shopping for a portable charger, the watt number tells you how fast it can push energy to your gear. Pick too low and charging drags; pick too high and you pay for speed you never use. This guide shows clear ranges by device, explains what the labels mean, and helps you match ports, cables, and safety rules to daily needs. You’ll learn how capacity differs from speed and when to step up a tier for gaming or video calls.
How Many Watts For A Power Bank: Quick Picks By Device
Use these target wattage ranges to choose a bank that fits your setup. The middle value in each range suits most users; step up within the range if you charge while using the device or run heavier apps.
| Device Type | Typical Charge Power | Suggested Bank Output |
|---|---|---|
| Phones (iPhone 12+ / Android PD) | 18–25W | 20–30W |
| Small Tablets / e-readers | 18–30W | 30W |
| Large Tablets (iPad Pro class) | 30–45W | 45W |
| Ultrabooks / Chromebooks | 45–65W | 65W |
| Workstation Laptops (USB-C PD) | 65–100W | 87–100W |
| Game Consoles (handheld / docked) | 18–45W | 30–45W |
| Action Cams / Earbuds | 5–15W | 18–20W |
What The Watt Number Actually Means
Watts measure power, which equals volts times amps (W = V × A). Power banks list a “max output,” such as 20W or 65W. That number is the top speed the port can deliver when the device asks for it. If your phone only negotiates 9V at 2.2A, it will peak near 20W even if the bank can do 65W. You won’t harm a phone with a higher-rated bank; it just charges at the rate the phone accepts.
Modern USB-C chargers talk to your device to set safe voltage and current. The common standard is USB Power Delivery (PD). Older PD tops out at 100W; the latest PD 3.1 “EPR” mode raises the ceiling to 240W for certain laptops and docks. A travel battery rarely goes that high, but it matters for larger machines and desk hubs.
Why Phones And Tablets Often Peak Around 20–30W
Fast charging on current phones lands near the 20–30W band. iPhone models from 12 onward reach their fast-charge target with a 20W adapter. Many Android phones use about 25W with USB-C PD or PPS modes. If your bank has a single 20–30W USB-C port, you’ll hit the speed your phone expects and avoid paying for unused headroom.
Tablets draw more, especially large screens. An iPad Pro class tablet can pull 30–45W when the battery is low. For that class, a 45W port keeps speeds sharp and leaves room to top up while streaming or sketching.
Picking Wattage For Laptops Without Guesswork
Here’s a simple rule: match the adapter wattage your laptop ships with. If the power brick says 65W, pick a bank with at least one 65W USB-C port. Many thin laptops sip 45–65W; performance models need 90–100W when working hard. A 100W bank won’t power every gaming rig, but it will run a wide set of USB-C laptops and keep the battery from dropping during normal use.
Cable quality matters. To pass more than 60W, you need a 100W-rated USB-C cable (often 5A). If a cable is limited to 3A, the combo will cap around 60W even if both the bank and device can do more.
Wattage Vs. Capacity: Two Different Numbers
Wattage is speed. Capacity is how much energy the bank stores. Capacity is named in milliamp-hours (mAh) or watt-hours (Wh). To estimate how many phone refills you’ll get, convert the bank’s mAh to Wh (mAh × 3.7V ÷ 1000 ≈ Wh), then divide by your phone battery’s Wh and factor in 10–20% losses.
A 20,000mAh pack holds around 74Wh. That size usually sits under the 100Wh flight limit for carry-on and still charges a phone several times or a small laptop once. Larger 26,800mAh units land near 99Wh, which stays within common rules.
Rules For Flying With Power Banks
Portable batteries belong in carry-on, not checked bags. Most airlines allow up to 100Wh without special approval, and up to two spares rated 101–160Wh with airline permission. Check your carrier’s page before long trips, and keep ports covered during flights to avoid accidental activation. See the FAA lithium battery rules for the exact wording.
Ports, Profiles, And Real-World Speed
Look for USB-C PD on the spec sheet. PD sets common voltage steps (5V, 9V, 15V, 20V) and, with PPS, allows fine steps that match phone requests. Multi-port banks often split power when two devices charge at once. A “65W bank” might do 65W on USB-C when used solo but drop to 45W + 18W when you add a second device. If you must charge a laptop and a phone together, pick a bank that lists per-port outputs that meet both at the same time.
Wireless pads on banks add convenience for earbuds and phones, yet they waste more energy and charge slower at the same watt rating. For road trips and flights, wired charging keeps heat lower and preserves the bank’s stored energy.
Which Watt Tier Fits Your Gear?
Use this table to match common watt tiers with real use cases. Pick the lowest tier that clears your device’s peak draw; step up one tier if you plan to charge two items at once or run a laptop while on video calls.
| Watt Tier | What It Runs | Good Pick When |
|---|---|---|
| 18–20W | Phones, earbuds, action cams | You want light, pocket-size speed for one phone |
| 25–30W | Fast-charge phones; small tablets | You need brisk phone top-ups and room for a tablet |
| 45W | Large tablets; some ultrabooks | You sketch, stream, or game while charging |
| 60–65W | Ultrabooks, Chromebooks | You work on a laptop and phone together |
| 87–100W | USB-C laptops under load | You want near-adapter speeds on the go |
Choosing The Right Power Bank Wattage For Everyday Use
If You Mainly Charge A Phone
Pick a bank with a 20–30W USB-C PD port. That matches fast-charge targets on modern iPhones and many Android phones without overspending. Add a second port if you often power a friend’s phone at the same time.
If You Split Between Phone And Tablet
Go 30–45W. You’ll keep tablets happy and still hit max speeds on phones. A 45W bank with two ports is a sweet spot for road trips and coffee shop work.
If You Carry A USB-C Laptop
Check the laptop’s original adapter. If it lists 65W, choose a bank with a single 65W USB-C port or a combined 65W when solo. For machines that ship with 90–100W bricks, choose a 100W bank and a 5A cable.
If You Game Or Stream While Charging
Bump one tier. Active use pushes draw higher. A handheld console can sip 18W while idle yet reach into the 30–40W range under load or in docked setups. A 45W bank keeps pace in those cases.
Specs That Matter Beyond The Watt Label
Per-Port Ratings
Scan the fine print for split outputs. If a spec sheet lists “65W USB-C solo; 45W USB-C + 18W USB-A dual,” plan your connections to fit those caps.
PD Versions And PPS
PD 3.0 covers up to 100W with standard steps. PD 3.1 adds 140–240W ranges for larger gear. Phones that use PPS can hold a steadier voltage, which trims heat and keeps speeds strong during the mid-charge window.
Cables And Labels
Use a USB-C cable rated for the job. For 100W charging, look for 5A e-marked cables. If a cable is unmarked, assume it’s 3A and plan for up to 60W.
Safety Features
Good banks include over-current, over-voltage, and thermal cutoffs. Quality brands list certifications and use decent cells. If a unit gets hot, stop using it and contact the maker.
Real Numbers Backing These Picks
Apple lists 20W as the threshold for iPhone fast charging on current models. Samsung phones use a 25W target with PD PPS. USB-IF confirms PD 3.1’s 240W ceiling and the older 100W limit for PD’s standard range. For flights, the FAA and TSA pages explain the 100Wh carry-on limit and the allowance for two spares in the 101–160Wh bracket with airline approval.
Buying Checklist So You Choose Once
- Match your highest-draw device: buy a bank that clears that watt need on a single USB-C port.
- Plan for two-device charging: confirm the shared output keeps both items happy.
- Balance capacity with travel: 74–99Wh packs suit frequent flyers.
- Mind the cable: pair 100W setups with 5A e-marked cords.
- Think about refill speed: pick a wall charger that can recharge the bank at 30–65W.
Method And Scope
Ranges here map common PD profiles to everyday devices, with airline limits and PD ceilings cross-checked against official sources. Exact speeds vary with battery level, heat, and cable quality.
Bottom Line Wattage Picks You Can Trust
Phone-only users do well with 20–30W. Mixed phone-and-tablet kits feel smooth at 45W. USB-C laptops ride best at 65W, while heavier notebooks prefer 87–100W with a 5A cable. Choose the lowest tier that clears your peak draw, and you’ll charge fast without overspending comfortably.