Most Anker power banks refill in 1–12 hours, shaped by capacity, USB-C PD input watts, and the wall charger you plug in.
Anker sells many batteries, from slim 5,000–10,000 mAh units to heavy 24,000 mAh packs with 140W two-way charging. Charge time isn’t a single number. It depends on the energy inside the pack, the maximum input the pack accepts, cable quality, and the wattage your wall charger can deliver. This guide gives clear ranges, model examples, and a simple way to estimate hours for your own setup.
Anker Power Bank Charge Time: What Affects It
Four levers set the pace:
- Capacity (mAh/Wh): More energy takes longer to refill.
- Input spec: USB-C PD packs that accept 18W, 30W, 45W, 65W, or 100–140W recharge far faster than 5–10W micro-USB units.
- Charger wattage: A battery that accepts 30W will crawl on a 10W brick, and sprint on a 30W+ PD charger.
- Losses & usage: Charging while the bank is powering devices, cold temps, and weak cables add time.
Real-World Ranges You Can Expect
Here are grounded ranges by class. These assume you start near empty and use a decent cable:
- 10,000 mAh class (≈37 Wh): ~4–6 hours on a 10W charger; ~2–4 hours with 18–20W PD.
- 20,000 mAh class (≈74 Wh): ~8–12 hours on 10W; ~6–7 hours with 18W PD; ~3–4 hours with 45W–65W PD if the pack supports it.
- 24,000 mAh performance packs with 140W input: ~1–1.5 hours with a 140W PD 3.1 charger; about ~2 hours with a 100W charger.
Popular Models And Their Stated Recharge Times
The table below compiles headline figures from official materials and product listings. Real times vary with charger, cable, and ambient temperature.
| Model | Max Input & Notes | Stated Recharge Time |
|---|---|---|
| Anker 737 Power Bank (PowerCore 24K) | USB-C PD 3.1 up to 140W two-way charging | ~1–1.5 hrs with 140W; ~2 hrs with 100W |
| Anker 525/535 Power Bank (PowerCore 20K class) | USB-C PD input ~18W (model-dependent) | ~6.5–7 hrs with 18W PD; 10–11 hrs on 5V/2A |
| PowerCore Essential 20000 (325) | USB-C or micro-USB input (non-PD on older units) | ~10–11 hrs via 5V/2A |
| Recent 20K with “Recharging Time” table in listing | Shows scaling at 15W, 20W, 100W inputs | ~7.5 hrs (15W); ~5.25 hrs (20W); ~2 hrs (100W) |
| 10K pocket banks | Typical 10–20W input; some Nano models take higher input | ~3–6 hrs depending on charger and model |
How To Estimate Your Own Charge Time
You can ballpark hours with a simple ratio:
Estimated hours ≈ (Battery energy in Wh ÷ Charger watts) ÷ charging efficiency
For USB-C PD banks, efficiency during input often lands near 0.85–0.90. Many packs print Wh on the label. If you only see mAh, convert using nominal cell voltage (3.7V). Example: a 20,000 mAh pack is about 74 Wh (20,000 × 3.7 ÷ 1000). On a true 18W PD input, time ≈ 74 ÷ 18 ÷ 0.88 ≈ 4.7 hours. Real use while charging, warm cells, or a weak cable can stretch that to ~6–7 hours.
Charger, Cable, And Port Choices Matter
Match the bank’s input rating with a charger that can deliver it. A 45W-capable bank needs a PD charger that can supply 45W profiles. Use a 5A USB-C cable for 100–140W input. Shorter, certified cables reduce losses. If your bank has both micro-USB and USB-C, use USB-C. The old port tops out at low wattage and adds hours.
Fast Standards In Plain Terms
USB Power Delivery raises the ceiling. Modern PD 3.1 goes up to 140–240W and negotiates the right voltage/current between charger and device. If your bank and charger agree on a higher PD profile, input climbs and the clock drops. You’ll see this live on the smart display of high-end models.
Model-By-Model Context
24K Class With 140W Input
Flagship units with 24,000 mAh and PD 3.1 can refill in about an hour on a 140W brick, or around two hours on a 100W charger. That pace is handy on layovers or short hotel stops.
20K Banks With 18W PD Input
Plenty of 20,000 mAh packs accept 18W on USB-C. Expect ~6–7 hours with a proper PD charger and a USB-C to USB-C cable. A basic 10W adapter can stretch the session near half a day.
Legacy 20K Without PD
Older “Essential” models charge via 5V/2A. The spec lands near 10–11 hours from low battery to full. Good for overnight top-ups, not quick turns.
10K Everyday Packs
These refill fast on a 20W PD adapter—often around 2–4 hours. On a 10W phone cube, plan for 4–6 hours.
Quick Math Examples
- 10K bank on 20W PD: 37 Wh ÷ 20 ÷ 0.88 ≈ 2.1 hrs.
- 20K bank on 18W PD: 74 Wh ÷ 18 ÷ 0.88 ≈ 4.7 hrs; add margin for heat or passthrough, you see ~6–7 hrs.
- 24K bank on 140W PD: 88.8 Wh ÷ 140 ÷ 0.90 ≈ 0.7 hr; many users see ~1–1.5 hrs with real-world losses.
External Standards And Why They Matter
PD profiles determine the input ceiling. Newer PD 3.1 adds higher fixed voltages and PPS, which lets the charger fine-tune voltage. That keeps input high and heat under control during the bulk phase of charging. If you match a PD 3.1 bank with a PD 3.1 charger and a 5A cable, you get the fastest, safest refills.
Want the spec basics from the source? See the USB Power Delivery overview for the official power levels. For an Anker example that lists one-hour refills with a 140W brick, check the brand’s 24K support notes linked on its service pages.
Estimated Hours By Charger And Capacity
This table uses the simple formula above with an 0.88 efficiency factor. It rounds to keep the numbers friendly. Your bank’s input limit still applies; if the pack only accepts 18W, a 65W charger won’t speed it up.
| Capacity Class | Charger (W) | Est. Full Charge Time |
|---|---|---|
| 10,000 mAh (≈37 Wh) | 10W | ~4.2 hrs |
| 10,000 mAh (≈37 Wh) | 20W | ~2.1 hrs |
| 20,000 mAh (≈74 Wh) | 18W | ~4.7–7 hrs* |
| 20,000 mAh (≈74 Wh) | 45W | ~1.9–3.5 hrs* |
| 24,000 mAh (≈88.8 Wh) | 65W | ~1.6–2.0 hrs |
| 24,000 mAh (≈88.8 Wh) | 100–140W | ~0.7–1.5 hrs |
*Range includes overhead for heat, cable losses, and any load during charging.
Fastest Way To Fill Your Anker Pack
- Check the input line: Find “Input” on the label or spec page. Match your wall charger to that wattage or higher.
- Use PD, not legacy ports: USB-C PD beats 5V micro-USB by a wide margin.
- Pick the right cable: For 100–140W input, use a 5A USB-C cable rated for e-marker, especially with PD 3.1.
- Avoid passthrough during refills: Charging a phone while filling the bank slows the session and adds heat.
- Keep it cool: Room-temp surfaces help the battery hold higher input longer.
Safety Notes You Should Know
Stick with properly rated chargers and certified cables. If a product page or support note lists a recommended wattage, follow it. If your battery was part of an old recall batch, retire it and contact the maker. Charge on a hard surface, away from bedding, and stop if you notice swelling or odor.
When Times Run Long
If you see slow refills, run a quick checklist: Are you using a PD charger that meets the bank’s input spec? Is the cable short and known good? Is the bank warm from recent use? Are you charging another device at the same time? Fixing any one of these often cuts hours off the session.
Pass-Through And Trickle Behavior
Some banks pass power through to devices while plugged in. This can be handy for small gadgets, yet it drags input down. Many models also taper to a lower wattage near the top to balance cell health and heat. That last 10–20% always takes longer than the first half.
Buying Tips If Fast Refills Matter
- Pick PD input first: Look for a stated input above 18W if you travel often.
- Watch for 100–140W input on 24K class: This brings hour-scale refills when paired with the right charger.
- Prefer a live input display: Screens that show “IN 65W” or time-to-full help you spot cable or charger mismatches.
- Bundle a matching wall charger: A 65W or 100W PD charger is a smart add for multi-device trips.
Bottom Line
Charge time tracks three things: battery size, the bank’s input spec, and the watts your charger can deliver under a good cable. Small 10K packs often finish in a few hours with PD. Mid-size 20K banks land near a work shift on basic 10W cubes, or around a long lunch with true PD input. Flagship 24K models with 140W input can swing from empty to full near the one-hour mark. Match the pieces, and your refill time will match the numbers above.