Most Anker power banks refill in 1–7 hours; a 24K model can recharge in ~1 hour with a 140W USB-C PD charger.
Charge time depends on battery size, the bank’s USB-C input rating, the wall charger’s wattage, and the cable. Pick the right combo and even a big 24,000 mAh pack can bounce back fast. Pick a weak adapter and the same pack will crawl. This guide shows real-world times for popular models, the math behind the hours, and the exact steps to speed things up without cooking your gear.
What Controls Charge Time
Four things set the clock:
- Capacity (mAh / Wh): More energy to refill means more time. Many 20,000 mAh packs store about 74 Wh; 24,000 mAh lands near 86 Wh.
- Input wattage limit: Each bank caps how much power it will accept. If the limit is 18W, a 100W brick won’t make it any faster.
- Charger and cable: You only get fast input if the adapter speaks USB-C PD (or PPS where supported) and the cable is rated for the current.
- Charging curve & heat: Fast at the start, slower near 80–100%. Warm gear pulls back to stay safe.
How Long Anker Power Banks Need To Recharge (By Model)
Below are common models with their rated or documented full-charge times using suitable USB-C PD chargers. Times are for 0–100%, single-bank charging, with an appropriate USB-C cable.
| Model & Capacity | Max USB-C Input | Full Recharge With PD Charger |
|---|---|---|
| Anker 737 Power Bank (24,000 mAh) | Up to 140W | ~1 hour with 140W; ~1.5–2 hours with 96–100W |
| Anker 537 Power Bank (24K For Laptop) | Up to 30W | ~4–4.5 hours with a 30W PD charger |
| Anker 525 Power Bank (20K) | Up to 18W | ~6.5 hours with an 18W PD charger |
| Anker 335 Power Bank (20K) | Up to 18W | ~6.5 hours with an 18W PD charger |
These ranges reflect the bank’s own input ceiling. If your wall adapter is weaker than the ceiling, expect longer sessions. If your adapter is stronger than the ceiling, the bank still sticks to its limit.
What USB-C PD Versions Mean For Speed
USB Power Delivery sets the rules for safe high-watt charging over USB-C. PD 3.0 tops out at 100W. PD 3.1 extends that to 240W with new voltage steps and EPR cables. That’s why some laptop-grade packs refill in about an hour with a 100–140W brick.
When you shop chargers and cables, look for the watt rating and PD version. If you own a high-input bank and a matching PD 3.1 adapter, you’ll see much shorter times than you would with a phone-class 20W cube.
Real-World Setup That Cuts Hours
- Match charger to input: Use a PD adapter that meets or slightly exceeds the bank’s input cap.
- Use a capable cable: For 100–140W, pick a certified USB-C cable rated for 5A (E-marker present).
- Plug the bank alone: Skip pass-through. Recharging a phone from the bank while the bank recharges adds heat and slows everything.
- Keep it cool: Room-temp charging keeps the fast part of the curve longer.
- Start early: Topping up from 20–80% is faster than pushing the last few percent.
Simple Math To Estimate Your Own Time
You can ballpark hours with one line:
Time (hours) ≈ Energy (Wh) ÷ Input Power (W) ÷ Efficiency
Most packs recharge at about 80–90% efficiency. As a safe rule, use 0.85 for the efficiency divider.
- 20,000 mAh pack: ~74 Wh ÷ 18 W ÷ 0.85 ≈ 4.8 h for the bulk phase; many users see ~6–6.5 h 0–100% due to the taper at the end.
- 24,000 mAh pack with 100W input: ~86 Wh ÷ 100 W ÷ 0.85 ≈ 1.0 h bulk; real 0–100% lands near ~1.5 h.
- 24,000 mAh pack with 140W input: ~86 Wh ÷ 140 W ÷ 0.85 ≈ 0.72 h bulk; many see just about an hour end-to-end.
Close Variant: How Long Anker Power Banks Take To Recharge (Model-By-Model)
Here’s how the model line maps to the right charger class and the kind of time you can expect at home.
24K Class Packs (Laptop-Grade)
These packs accept far more input than phone-class banks. Paired with a 100–140W adapter and a 5A cable, they race from empty to full.
- 24,000 mAh with PD 3.1 input: ~1 h with 140W; ~1.5–2 h with 96–100W.
- 24,000 mAh with 30W input: ~4–4.5 h with a 30W PD adapter.
20K Class Packs (Phone/Tablet-Focused)
These top out near 18–20W input. They work fine with a common 20W phone charger, but they don’t get faster with a big laptop brick because the bank itself limits input.
- 20,000 mAh with 18W input: ~6–6.5 h with an 18W PD adapter.
Picking The Right Charger And Cable
Use a single-port PD charger when you can. Multi-port chargers share power across ports. If another device is plugged in, your bank might only get a slice. For high input banks, look for 100W or 140W PD and an E-marked USB-C cable rated to 5A. This combo keeps high-watt charging stable, which trims time and heat.
Safety And Battery Care While Recharging
Lithium cells like gentle treatment. Don’t cover the bank while it’s refilling. If the shell feels hot, give it space, then plug back in. Skip pass-through charging sessions unless you must. If a pack starts swelling or takes much longer than it used to, retire it at a proper e-waste site.
For the charging standard details, see USB Power Delivery 3.1. For a model-specific note on a fast-charging 24K pack, check Anker’s guidance on 737 recharging time.
Troubleshooting Slow Refill
Wrong Charger Mode
Some adapters default to shared power across ports. Unplug other devices. If your adapter has a “high-power” solo port, use that one.
Weak Cable
A cable without an E-marker often tops out at 3A. That’s fine for phone-class banks, not for 100–140W input. Swap in a 5A cable.
Low-Watt Wall Brick
A 20W cube feeding a 24K laptop-class pack will crawl. Upgrade to a 100W or 140W PD brick that matches the bank’s ceiling.
Hot Room Or Stuffy Bag
Heat triggers a slowdown. Charge on a hard surface with airflow. Avoid stacking devices while the bank fills.
Pass-Through Charging Active
If the bank is powering a device while refilling, the input is partially diverted. Unplug the phone or laptop to let the bank finish first.
Second Table: Quick Estimates By Capacity Tier
Use these ballpark figures when you don’t have a model page handy. Times assume a healthy bank, single-device charging, and a suitable cable.
| Capacity Tier (Approx. Wh) | Wall Charger (PD) | Estimated 0–100% Time |
|---|---|---|
| 10,000 mAh (~37 Wh) | 20W | ~2–3 hours |
| 20,000 mAh (~74 Wh) | 18–20W | ~6–6.5 hours |
| 24,000 mAh (~86 Wh) | 30W | ~3–4.5 hours |
| 24,000 mAh (~86 Wh) | 96–100W | ~1.5–2 hours |
| 24,000 mAh (~86 Wh) | 140W | ~1 hour |
Model-Specific Notes You’ll Care About
24K With PD 3.1 Input
Packs with 140W two-way PD can refuel near the one-hour mark when paired with a 140W adapter and a 5A cable. Drop to a 96–100W brick and you’ll land around 1.5 hours. These numbers assume the bank is idle and cool.
24K With 30W Input
Some 24K units cap at 30W input. They refill in around 4–4.5 hours with a 30W PD adapter. Bigger bricks don’t change that limit.
20K With 18W Input
Classic 20K banks sit near 6–6.5 hours with an 18W PD charger. They’re steady, just not quick. A stronger charger won’t bypass the bank’s 18W gate.
Speed Checklist Before You Plug In
- Find the bank’s input limit on the spec label or product page.
- Grab a PD adapter that meets that number (or the closest step).
- Use a certified USB-C cable. For 100–140W, pick a 5A E-marked cable.
- Charge the bank by itself on a hard surface.
- Let it cool if it gets warm, then finish the last stretch.
Care Tips That Keep Times Consistent
- Store around mid-charge if you won’t use it for a while.
- Avoid deep drains every single cycle.
- Keep it away from hot cars and direct sun.
- Recycle at an e-waste site once performance drops or the shell swells.
Bottom Line On Anker Power Bank Charge Times
Small banks finish in a few hours with a phone-class adapter. Classic 20K packs need around 6–6.5 hours at 18–20W. Laptop-grade 24K units blaze through in about an hour with a 140W PD 3.1 brick and a 5A cable, or around 1.5–2 hours with a 96–100W adapter. Match the charger to the bank’s input limit, use the right cable, keep things cool, and you’ll hit the fastest safe time your model allows.