The basics: what you need to know before you plug in

Anker power banks charge through a USB cable — usually USB-C or micro-USB, depending on your model. Plug the cable into the power bank's input port (the one marked for charging the bank itself, not the output ports where you charge your phone), then plug the other end into a wall outlet, car charger, or computer USB port. Most Anker banks take 4 to 8 hours to charge fully from empty, though this varies by capacity and the wattage of your charger.

The speed of charging depends on two things: the power adapter you use and the power bank's input rating. An Anker power bank rated for 18W input will charge faster with an 18W adapter than with a 5W phone charger. Check your power bank's manual or the label on the back to see its input wattage, then use an adapter that matches or exceeds that rating.

You can charge your power bank and use it to charge your phone at the same time — this is called pass-through charging. However, it will charge more slowly because the power is split between the two tasks. If you need your phone charged quickly, charge the power bank first, then use it to charge your phone.

Key Takeaways

  • Plug the USB cable into the power bank's input port (not the output ports), then into a wall outlet, computer, or car charger.
  • Match your charger's wattage to your power bank's input rating for the fastest charge — check the label on the back of the bank.
  • A full charge typically takes 4 to 8 hours depending on capacity and charger wattage.
  • Pass-through charging (charging the bank and your phone at the same time) works but slows both charges down.
  • Stop charging once the LED indicator shows full, or unplug after a few hours, to avoid keeping the battery at 100% for extended periods.

Finding the right input port on your Anker power bank

Anker power banks have two types of ports: input ports (where you charge the bank) and output ports (where you charge your devices). The input port is usually labeled with an arrow pointing inward or marked "Input" on the back or bottom of the bank. Most newer Anker models use USB-C for input; older models use micro-USB.

The output ports are where you plug in your phone or other devices. These are usually labeled with an arrow pointing outward or marked "Output." Some Anker banks have multiple output ports — USB-A, USB-C, or both — so you can charge more than one device at a time. Do not plug your charging cable into an output port by mistake; it will not charge the power bank.

If you are unsure which port is which, check the manual that came with your power bank or look at the label printed on the device itself. Anker also prints the specifications on the back, including input and output wattages.

Choosing the right charger and cable for your power bank

The charger you use matters. An Anker power bank with 18W input will charge in roughly half the time with an 18W USB-C charger compared to a standard 5W phone charger. Check the input rating on your power bank's label, then use a charger with equal or higher wattage.

The cable also matters. A damaged or low-quality cable can slow charging or prevent it from working at all. Use the cable that came with your Anker power bank if possible. If you need a replacement, buy a certified USB-C or micro-USB cable from a reputable seller — Anker's own cables are reliable, but other brands like Belkin and Amazon Basics also work well.

Avoid using very old chargers or chargers from unknown brands. A charger rated for much higher wattage than your power bank needs is fine — the power bank will only draw what it needs — but a charger rated for much lower wattage may charge slowly or not at all.

Understanding the LED indicator lights

Most Anker power banks have LED lights that show the current charge level. A full row of lights means the bank is fully charged; fewer lights mean it still has room for more charge. Some models use a single light that blinks or changes color as the bank charges.

When you first plug in your power bank to charge, the lights should turn on or begin blinking. If nothing happens, try a different cable or charger — the problem is usually a faulty cable rather than a broken power bank. If the lights still do not appear, the power bank may need to be charged for several minutes before the indicator activates.

Once the lights show a full charge, you can unplug the bank. Leaving it plugged in after it reaches 100% will not damage it — Anker power banks have built-in protection that stops charging once full — but unplugging it after a few hours is better for long-term battery health.

Charging times for different Anker power bank sizes

Smaller Anker power banks (5,000 to 10,000 mAh) typically charge in 2 to 4 hours with a standard 5W charger, or 1 to 2 hours with an 18W charger. Mid-size banks (20,000 to 25,000 mAh) take 4 to 6 hours with 5W input, or 2 to 3 hours with 18W or higher. Larger banks (30,000 mAh and above) can take 6 to 8 hours with standard chargers, or 3 to 5 hours with fast chargers.

These times are estimates and will vary based on the exact model, the charger wattage, and the cable quality. A higher-capacity bank charged with a low-wattage charger will take longer than the estimate. Conversely, using a fast charger with a high-capacity bank will be faster than charging with a standard 5W adapter.

If you want to know the exact charging time for your specific model, check the product page on Anker's website or the manual that came with your power bank. Both usually list charging times for different charger wattages.

What to do if your power bank is not charging

If your Anker power bank is not charging, start with the cable. Unplug it, wait 10 seconds, and plug it back in using a different cable if you have one. Many charging problems are caused by a damaged or loose cable rather than a broken power bank.

Next, try a different charger. If you were using a low-wattage charger, try a higher-wattage one. If you were using a computer USB port, try a wall outlet instead — computer ports often provide less power. If the power bank charges with a different charger or cable, the original one is faulty and should be replaced.

If the power bank still does not charge with multiple cables and chargers, it may have a hardware problem. Anker power banks come with a warranty — check your receipt or the Anker website to see if your bank is still covered. Contact Anker support with your purchase date and model number; they can often replace a defective unit.

Keeping your power bank healthy during charging

Avoid charging your power bank in very hot environments. Heat degrades lithium batteries over time, so do not leave your power bank in direct sunlight, in a hot car, or next to a heat source while charging. Room temperature is ideal.

Do not charge your power bank to 100% and leave it plugged in for days or weeks. If you plan to store it for more than a month, charge it to about 50% and unplug it. This slows battery aging. When you are ready to use it again, charge it fully before relying on it.

If your power bank gets wet, let it dry completely before charging it. Moisture in the ports can cause a short circuit. Wipe the ports with a dry cloth and wait at least 24 hours before plugging it in.

Frequently Asked Questions

Can I use any USB charger to charge my Anker power bank?

Yes, any USB charger will work, but the wattage matters. A charger with higher wattage than your power bank's input rating will not damage it — the bank will only draw what it needs. A charger with much lower wattage will charge slowly or not at all. Check your power bank's input rating and use a charger that matches or exceeds it.

How long does an Anker power bank hold a charge when not in use?

Most Anker power banks hold their charge for several weeks to a few months when not in use. The exact time depends on the model and capacity. If you plan to store a power bank for longer than a month, charge it to about 50% and keep it in a cool, dry place. This helps preserve battery health.

Is it safe to charge my phone and power bank at the same time?

Yes, pass-through charging is safe. Your phone and power bank will both charge, but more slowly because the power is split. If you need either device charged quickly, charge the power bank first, then use it to charge your phone.

Why is my Anker power bank charging slowly?

The most common reasons are a low-wattage charger, a damaged cable, or a loose connection. Try a different cable or a higher-wattage charger. If you are using a computer USB port, try a wall outlet instead. If the power bank charges normally with a different setup, the original cable or charger is the problem.

Can I leave my Anker power bank plugged in overnight?

Yes, it is safe — Anker power banks have built-in protection that stops charging once the battery is full. However, for long-term battery health, unplugging after a few hours is better than leaving it plugged in for extended periods. If you charge it overnight regularly, consider unplugging it once it reaches full capacity.