Most Anker power banks take about 1–12 hours to recharge, depending on capacity and charger wattage; high-input models can refill in under 90 minutes.
If you landed here to figure out how long an Anker power bank needs on the wall, you’ll get a clear answer fast, plus a simple way to estimate your own time. The short version: total capacity and the charger’s input watts set the pace, while cables, temperature, and the last few percent add delay. Below you’ll find real numbers for common sizes and a calculator you can use for any model.
Estimated Charge Times By Capacity And Charger Power
This table gives realistic full-charge windows for common sizes across a range of USB-C inputs. These are whole-unit times from near empty to 100% under room-temp conditions.
| Capacity Class | Charger Input (W) | Full Charge Time |
|---|---|---|
| 10,000 mAh (~37 Wh) | 18 W | ~2.4 hours |
| 10,000 mAh (~37 Wh) | 30 W | ~1.5 hours |
| 20,000 mAh (~74 Wh) | 18 W | ~4.8 hours |
| 20,000 mAh (~74 Wh) | 30 W | ~2.9 hours |
| 24,000 mAh (~89 Wh) | 60 W | ~1.7 hours |
| 27,000 mAh (~100 Wh) | 140 W | ~0.8 hours |
These estimates assume about 85% energy efficiency through the charge path and steady input power. That aligns with independent battery data showing round-trip efficiency in the 80–90% band, and with USB-C PD power levels that reach well beyond 100 W for capable gear. For background on the power standard, see USB Power Delivery.
What Affects Recharge Duration
Capacity Sets The Floor
Capacity is energy. A 10,000 mAh pack sits near 37 Wh, a 20,000 mAh pack near 74 Wh, a 24,000 mAh pack near 89 Wh, and a 27,000 mAh pack near 100 Wh. Time is simply energy divided by input watts, adjusted for conversion losses. Double the capacity with the same charger and the wait around doubles.
Input Watts Make The Biggest Difference
USB-C Power Delivery lets the bank accept far more than old 5 V bricks. Feed a 20,000 mAh unit with an 18 W cube and you’re in the 5-hour ballpark. Step up to 60 W and you cut that to around two hours. Flagship units that accept 140 W or more can refuel in well under 90 minutes when paired with a matching charger and a high-rating cable.
Cables And Ports Matter
High-rate charging needs a cable rated for the job and a charger that can negotiate the higher PD profiles. A cable certified for the newest PD levels ensures the bank can draw the watts it’s built for. If the cable tops out below the bank’s input ceiling, the session will throttle.
Temperature And The Top-Off Phase
Cold cells, very warm rooms, or restricted airflow all slow the end of a charge. The last 10–20% often tapers, so a “0–80%” claim can look much faster than a full run to 100%. Give the bank a little space on a desk and avoid charging inside a hot pack or under blankets.
How Long To Recharge Anker Power Banks Safely
Here are two concrete reference points from Anker’s current lineup so you can gauge the range across classes:
Power Bank 24K (known as 737): with a capable USB-C charger from Anker’s list, the brand states a 0–100% window of about 1–1.5 hours. See Anker’s own recharging time guidance for this model.
Prime Power Bank 27K (250 W class): the product page calls out a full refill in under 43 minutes by taking advantage of a 140 W input over USB-C. That number assumes a high-power PD source and a compatible EPR cable; see the product spec.
These figures show the spread: mid-size packs on modest bricks land in the multi-hour range, while top-tier input levels compress the wait dramatically.
Estimate Your Own Charge Time
Use this quick method for any model, even if the label doesn’t print hours:
Step 1: Convert mAh To Wh
Multiply capacity (mAh) by 3.7, then divide by 1000. That turns milliamp-hours into watt-hours. A 20,000 mAh bank is near 74 Wh.
Step 2: Divide By Charger Watts
Divide your Wh by the input rating of the bank (not just the brick). If the bank’s USB-C input tops out at 30 W, use 30 W even if your brick says 65 W.
Step 3: Add Real-World Overhead
Multiply the result by ~1.15–1.2 to account for conversion and tapering. That margin aligns with published energy-efficiency ranges for lithium packs and DC-DC conversion.
Worked Example
Say your pack is 24,000 mAh (≈89 Wh) and the spec sheet lists a 60 W USB-C input. 89 ÷ 60 is 1.48. Add 20% for overhead and you land near 1.8 hours from low to full.
Real Models And Stated Windows
To anchor the math with brand statements, here’s a small set of current notes drawn from Anker’s pages.
| Model Or Class | Max Input (W) | Stated Or Typical Time |
|---|---|---|
| Power Bank 24K (737) | Up to 140 W | ~1–1.5 hours (brand guidance) |
| Prime 27K (250 W class) | Up to 140 W | Under 43 minutes (product page) |
| 20,000 mAh with 10 W brick | 10 W | ~10–12 hours (brand blog) |
Pick The Right Charger And Cable
Match The Bank’s Input Ceiling
Check the spec sheet or the tiny print near the USB-C port for the highest input in watts. Pair a charger that can supply that number on one port. A 65 W multi-port block that splits power may fall short if other devices are connected.
Use A Cable Rated For High PD
For any bank that can take 100 W or more, use a cable designed for the newest PD levels. The latest PD standard allows up to 240 W on the right gear, which avoids bottlenecks when a high-draw bank negotiates over USB-C.
Keep Sessions Efficient
Give the pack a straight shot: desk surface, open air, and a charger plugged directly into the wall. Long daisy chains or bargain power strips add drop and heat. If the bank has a screen that shows input watts, confirm you’re near the rated ceiling.
Why 0–80% Feels Faster Than 80–100%
Most packs charge in two broad stages: a current-limited ramp that fills fast, then a voltage-limited top-off that slows to protect the cells. That second slice can take as long as the first slice, which is why a “90 minutes to 80%” claim can coexist with a “two hours to full” reality.
Care Tips That Preserve Speed Over Time
Avoid Deep Drains
Running to zero and storing flat ages the pack. Frequent mid-range top-ups keep the chemistry happier and help the bank accept higher charge rates longer into its life.
Charge At Room Temp
Very cold or very hot sessions drag. Room-temp charging keeps the taper shorter and the estimate closer to the math.
Store Near Half When Idle
If you won’t use the bank for weeks, park it near the middle of the gauge. That leaves room for self-discharge without stressing the cells.
Troubleshoot Slow Recharges
Confirm The Input Ceiling
Look for the “Input” line on the label or spec page. If the bank lists 30 W in, a 100 W brick won’t speed it up. Pick a single-port charger that can deliver that number without sharing.
Check The Cable Rating
Many USB-C cables cap at 60 W. A bank that can draw 100–140 W needs an EPR-rated cable. Swap the cable and watch the input watts rise on the bank’s screen if it has one.
Eliminate Power Sharing
Unplug other devices from a multi-port brick during a refill. Shared ports split capacity, which drags the intake rate.
Give It Air
Heat slows the top-off. Move the bank off soft fabric and out of direct sun. A cool, airy desk knocks minutes off long sessions.
Travel Notes And Safety
Airlines follow watt-hour limits for loose lithium packs. In the United States, carry power banks in hand luggage only. The Federal Aviation Administration lists the limit as 100 Wh per unit, with airline approval for up to two spares in the 101–160 Wh range. See the FAA’s PackSafe guidance and the TSA page for power banks.
Bottom Line On Charge Time
If you match the bank’s input rating with a capable PD charger and a high-rating cable, you can predict the wait with simple math. Small packs on small bricks land in a two-to-five-hour range. Large packs with high input draw can be back to full in about an hour. Pick your charger once, pack the right cable, and you won’t be guessing the clock at the outlet.