Charge time for Anker power banks ranges from under 45 minutes to 12 hours, depending on capacity, input watts, and the charger you use.
An Anker battery packs energy in milliamp hours, but refilling it depends on three levers: the pack’s input limit, the wall charger’s wattage, and the cable. Pick the right combo and a large pack goes from empty to full fast; mismatch them and the same pack crawls. This guide gives real charging times you can trust, plus simple picks to hit the fastest turnaround without guesswork.
Typical Charge Times By Popular Models
Below is a quick reference for well-known Anker packs. Times assume no pass-through and a healthy cable. Real-world results can vary a little with temperature and background device use.
| Model | Capacity | Full Recharge Time (Best-Case) |
|---|---|---|
| Anker Prime 27,650mAh (250W) | 27,650mAh | ~43 minutes with 140W USB-C input |
| Anker 737 Power Bank (PowerCore 24K) | 24,000mAh | ~1–1.5 hours with a 120–140W USB-C charger |
| Anker 537 Power Bank (PowerCore 24K for Laptop) | 24,000mAh | ~3.5–4.5 hours with a 30W USB-C charger |
| Anker 325 / PowerCore 20K | 20,000mAh | ~10–12 hours with a 5V/2A charger (legacy input) |
Charging Time Formula That Actually Works
You can estimate charge time with a simple back-of-the-envelope math: divide energy by power, then add overhead. A 20,000mAh pack stores about 74Wh (20Ah × ~3.7V). Feed it with a 30W USB-C input and the theoretical minimum is 74Wh ÷ 30W ≈ 2.5 hours. Real packs waste some energy as heat and end the cycle slowly, so add roughly 20–30%. That lands near 3–3.5 hours—close to what fast USB-C models show in practice.
Charging An Anker Power Bank: How Long It Takes
Wondering about recharging an Anker portable battery from zero? The time depends mostly on the input wattage the pack accepts and the wall brick you plug in. The next sections break it down step by step.
What Dictates The Refill Speed
The Pack’s Input Limit
Every model lists a maximum input. Newer USB-C designs accept 30W, 60W, 100W, or even 140W. Older micro-USB units accept only 10W (5V/2A). A charger stronger than the pack’s input limit won’t help past that ceiling.
The Wall Charger’s Output
Match the wall brick to the pack’s ceiling. A 65W USB-C PD charger covers most modern Anker packs and doubles as a laptop brick. If the pack tops out at 30W, a compact 30W brick is enough.
The Cable Rating
USB-C cables now carry power ratings. Certified 60W or 240W labels tell you what they can safely deliver. Using a low-rated cable on a high-input pack can cap the speed. The USB-IF explains these labels on its public page; tap the mid-article link below to check the official guidance.
Model-Specific Notes You Can Rely On
Prime 27,650mAh (250W)
This flagship supports up to 140W USB-C input. With a matching brick, a full refill lands under 43 minutes. That’s possible because the pack accepts very high power for most of the cycle.
737 Power Bank (PowerCore 24K)
With a capable USB-C PD brick in the 120–140W range, users report roughly one hour to a full tank, with published guidance placing the window at about 1–1.5 hours. You’ll see an Anker service note linked below with the same ballpark.
537 Power Bank (PowerCore 24K For Laptop)
This 24,000mAh model accepts a 30W maximum input. Expect about 3.5–4.5 hours with a PD 30W wall charger when the pack isn’t powering anything else. The official help article listed below matches that figure: Anker 537 recharging details.
PowerCore 20K Legacy Models
Units with 5V/2A input need patience. Twelve hours is common on a basic phone charger. Upgrading the brick won’t help unless the pack itself supports USB-C PD input.
Step-By-Step: Get The Fastest Possible Refill
- Find the input spec on the pack’s label or product page. Look for “USB-C input” followed by watts or volts/amps.
- Pick a wall charger that meets or slightly exceeds that number. No need to overspend well beyond the ceiling.
- Use a certified 60W or 240W USB-C cable. Avoid unmarked cables from junk drawers.
- Charge the pack by itself. Skip pass-through and unplug devices until the pack is topped off.
- Keep it cool and flat while charging. Heat slows the final percent and shortens lifespan.
Why USB-C PD Levels Matter
USB Power Delivery now extends up to 240W with the latest spec. That’s how modern power banks accept 100W+ input and finish so fast. If you want the source, check the USB-IF overview. Pair a high-input pack with a 140W brick and a 240W-rated cable to reach peak speed.
Real-World Tips That Save Time
Top Off Frequently
Large lithium packs prefer partial cycles. A quick one-hour top-up before a trip beats running from near empty every time.
Skip The Random Cable
Stick to labeled USB-C cables with clear 60W or 240W marks. That avoids hidden bottlenecks and heat.
Mind The Last 10%
Fast charging slows near the end to protect cells. If you only need enough for the day, stopping at 80–90% can cut wait time.
Travel-Safe Capacity
Most airline rules allow packs up to 100Wh in carry-on. Many Anker models sit just under this cap, including the big 24K and 27K units.
Charge Time Scenarios
• 24,000mAh pack with 140W input on a 140W brick: plan for around one hour, sometimes less.
• 24,000mAh pack with 30W input on a 30W brick: plan for about four hours.
• 20,000mAh legacy pack on a 5V/2A phone charger: plan for an overnight stretch.
• 10,000mAh compact pack on a 20W brick: plan for roughly two to four hours, depending on efficiency.
What Your Charger Choice Changes
Here’s how one large pack behaves with different bricks. Same battery, different inputs, very different wait times.
| Wall Charger | Input Delivered | Approx. Full Time |
|---|---|---|
| 140W USB-C PD 3.1 | Up to 140W | ~45–60 minutes on high-input packs |
| 65W USB-C PD | Up to 65W | ~1.5–2.5 hours on 60–100W input packs |
| 30W USB-C PD | Up to 30W | ~3–4.5 hours on 30W input packs |
Troubleshooting Slow Recharges
It’s Taking Way Too Long
Check the charger’s wattage and the pack’s input spec. Plug into the USB-C port labeled “PD” or “100W/140W.” Try a different outlet and a known-good cable. Remove any phone or laptop drawing power from the pack while it’s refilling.
LEDs Stall Near Full
That taper is normal. The final percent can linger as the battery balances. If it never finishes, swap cable and brick to isolate the cause.
Old Micro-USB Pack
Legacy models can need 10–24 hours. If you rely on a bank often, upgrade to a USB-C PD unit with at least 30W input and pair it with a matching brick.
Recommended Pairings For Fast Turnarounds
• Big pack with 140W input → 140W USB-C PD brick + 240W cable.
• 60–100W input pack → 65–100W USB-C PD brick + 100W or 240W cable.
• 30W input pack → compact 30W USB-C PD brick + 60W cable.
Battery Health While Fast Charging
Fast input is safe when the pack, charger, and cable are built for it. Keep the pack out of direct sun, give the vents room, and avoid thick blankets over it. If the shell feels hot, pause for fifteen minutes and resume later. Storing around half charge for long breaks helps as well. Keep cables tidy.
Method And Sources
Times above are drawn from published Anker guidance for specific models and from the USB-IF’s public pages on USB-C PD power levels. The 537 laptop pack and the 27K Prime unit publish the high-level numbers used here. Link targets open in a new tab.