Why Does My Anker 100W Charger Pause When I Plug In Another Device?

If your Anker 100W 3-Port Charger with Smart Display (B121B) briefly pauses charging when you connect or disconnect another device, that behaviour can be normal. Anker's official product FAQ says the charger redistributes power when switching between two-port and three-port use, which can cause a short charging interruption.

This guide explains what is happening, how the B121B divides its 100W maximum output, what the smart display is showing, and when a pause may point to a cable, device or connection problem instead.

Quick answer

The B121B has two USB-C ports and one USB-A port. When the number of connected devices changes, the charger may need to renegotiate and redistribute available power between ports. Anker specifically documents that a brief interruption can occur when switching between two and three ports. That is different from repeated disconnecting every few minutes, which deserves troubleshooting.

How the Anker B121B distributes power

Anker rates the charger at 100W maximum total output. With one compatible device connected to either USB-C port, that USB-C port can provide up to 100W. With multiple devices connected, the available output is shared rather than giving every port 100W at the same time.

Anker lists USB-C1 + USB-C2 allocations of 70W + 30W or 95W + 5W depending on the connected devices. For USB-C plus USB-A, Anker lists 67W + 33W or 95W + 5W. With all three ports in use, the published allocation is 80W + 12W + 7.5W. Your device still decides what power it can accept, so the number shown on the charger is a capability, not a promise that every phone or laptop will draw that amount.

Why charging can stop for a moment

Adding a second or third device changes the charger's job. It has to detect the new load, decide how to divide available power and let connected USB-C devices negotiate an appropriate charging profile. During that transition, a device may briefly show that charging stopped and then resumed.

If the interruption happens once when a device is plugged in or removed, and charging then continues normally, it matches the behaviour Anker describes for this model.

What the smart display is telling you

The B121B's smart display shows real-time charging information including port performance, power, voltage and temperature. Anker also notes that charging power naturally changes with battery level, screen activity and temperature protection. So a lower number on the display does not by itself mean the charger is faulty.

Why low-power devices can change the allocation

Anker documents a low-current mode for this charger. If USB-C2 or USB-A remains at 5W or below for about one minute, the charger can switch to a 95W + 5W allocation. This is intended for combinations such as a higher-demand device plus earbuds, a watch or another low-power accessory.

When should you troubleshoot instead?

A single brief pause during a port change is different from unstable charging. Check your setup if a device repeatedly disconnects and reconnects without you touching the charger, if a connector feels loose, if a cable is damaged, or if charging does not resume after the port change.

1. Check the cable

For high-power USB-C charging, the cable matters. A cable that cannot carry the requested power can limit the setup even when the charger itself has enough capacity. Check the device manufacturer's charging requirements and use a suitable USB-C cable. Our USB-C cable wattage guide explains why the wattage printed on a cable is separate from the charger's total output.

2. Test one device at a time

Disconnect the other devices and test the problem device alone on USB-C1, then USB-C2 if appropriate. If it charges normally alone but changes behaviour only when other devices are added, power redistribution is a likely explanation.

3. Check the device's own input requirements

A 100W charger cannot make a device accept 100W. Phones, tablets, laptops, earbuds and watches have their own charging limits and supported protocols. For a simple explanation of negotiation, see our USB Power Delivery guide for Pakistan.

4. Look for physical or abnormal warning signs

Stop using equipment that has damaged insulation, cracked casing, bent or loose pins, sparking, a burning smell or other abnormal physical behaviour. Do not treat repeated instability as normal simply because one brief port-switch interruption is documented.

Which port should you use for a laptop?

With a single compatible laptop, either USB-C port is rated by Anker for up to 100W. When several devices are connected, the allocation changes. If your laptop needs the larger share, check the display and the published port allocation rather than assuming all three ports provide their single-port maximum simultaneously.

For households charging several brands and device types, our multi-device household charger guide covers the buying decision more broadly.

Is the Anker B121B suitable for Pakistan?

Anker's official specification lists a 100-240V~, 50/60Hz input for the B121B. However, plug shape and regional package contents can vary, so check the exact product images and delivered retail package before ordering rather than assuming a universal physical plug fit.

AvaNext currently lists the Anker 100W 3-Port Charger with Smart Display - B121B. Check the live product page for current price, stock and the exact listing details. You can also browse the Anker Pakistan collection to compare alternatives.

Should you buy 100W just for a phone?

Not necessarily. The strongest reason to choose a 100W three-port charger is usually flexibility: a laptop or other higher-demand USB-C device plus phones and smaller accessories from one adapter. If you only charge one phone, a lower-wattage compatible charger may be simpler and more economical.

If you are comparing this model with another 100W option, read Apple 100W vs Anker 100W in Pakistan for a different buying-decision angle.

Frequently asked questions

Is a brief charging pause normal when I connect another device?

For the B121B, Anker says a short interruption can occur when the charger redistributes power while switching between two-port and three-port use.

Does each USB-C port provide 100W when three devices are connected?

No. Up to 100W is available from a USB-C port in the relevant single-port configuration, but the total power is redistributed when multiple ports are used.

Why does the display show less power than my device's advertised charging wattage?

Actual draw can vary with battery level, device activity, temperature management, the cable and the charging protocol negotiated by the device.

Can I charge earbuds or a smartwatch alongside a laptop?

The charger is designed to support low-power devices, and Anker documents a low-current allocation mode. Actual compatibility still depends on the connected device and cable.

Bottom line

If your Anker B121B pauses once when you add or remove another device and then resumes charging, that can be normal power redistribution. If charging repeatedly drops without a port change, inspect the cable, device connection and physical condition of the setup. For buyers who genuinely need laptop-class output plus extra ports, the B121B's value is not simply the 100W label; it is the ability to manage several different charging loads from one adapter.

Manufacturer facts in this guide were checked against Anker's official B121B product documentation on 2 September 2026. Regional package contents and plug style should be confirmed on the live listing before purchase.