How to compare charging after a software update

Your laptop, tablet or phone seems to charge more slowly since a software update. That can happen if the device is busy installing updates or syncing files, but a change in charging settings, temperature or the charger setup can look similar.

Use the Charger & Cable Test to compare the reported charging rate in percent per minute. The key is to keep the test conditions alike, so you can tell whether the change is consistent rather than a temporary difference.

Compare the charging rate

Open the Charger & Cable Test on the device you are charging. The test is available only when the browser reports battery information. If it does not appear, the browser or device may not provide the data needed for this test.
Use the same charger, cable and wall outlet as before the update. If you have a saved result from before the update, note its charging rate in percent per minute and the conditions you used.
Start at a similar battery percentage to the earlier test. For example, compare two runs that both begin around 30 to 50 percent, rather than comparing a low battery with one that is nearly full.
Keep the device in a similar state during each run. Use the same screen brightness and leave it idle, or use it in the same way for both tests. Let the test observe charging for the same amount of time.
Compare the reported percent per minute. If the result is different, repeat the test once under the same conditions before changing settings.

If you did not measure charging before the update, you cannot confirm that the update caused the change from a current test alone. You can still compare the charger and cable with another known-good setup, using the same device, starting charge level and test conditions.

What the result means

The rate is close to your earlier result

The update has not caused an obvious change in the measured charging rate. A small difference can come from rounding, battery percentage estimates or ordinary variation. If the battery still takes much longer to fill, look for changes in how you use the device, its temperature, or a charging limit that stops it before 100 percent.

The rate is lower in repeated tests

A consistent drop means the device is gaining charge more slowly under those conditions. It does not prove that the update damaged the battery or charger. Background activity, a changed power setting, heat, or a cable or outlet problem can all affect the result. Work through the checks below.

The rate changes as the battery fills

Charging often slows as the battery approaches full. A device may also pause or limit charging to manage heat or follow a charging schedule. Compare runs that start in a similar charge range, and do not treat a slower rate near full as proof of a fault.

The test is missing or shows no battery data

Some browsers and devices do not report battery information to web pages. That is a browser limitation, not evidence that charging has stopped. Check the charging icon and percentage in the device itself, or use another supported device browser if available.

How to check for a change

Let update activity finish. After an update, the device may still be downloading apps, syncing files or completing setup tasks. Leave it plugged in and idle for a while, then repeat the test when that activity has settled.
Keep the device cool and idle. Heat can cause a device to limit charging. Remove a thick case if the device feels warm, place it on a hard surface, and avoid gaming, video calls or other heavy use during the comparison.
Check power and charging options. In Windows 11, open Settings › System › Power & battery and review the current power settings. On macOS, open System Settings › Battery and review battery health and charging options available for your Mac. On an iPhone, check Settings › Battery for charging or battery health options. On Android, open Settings › Battery and look for charging optimization or adaptive charging. Names and options vary by device.
Check for a charge limit. Some laptops and phones are set to stop charging around 80 percent to reduce battery wear. Laptop makers may place this setting in their own system utility. Compare charging below the limit, and do not assume the device is faulty because it stops at a chosen threshold.
Try the charger, cable and outlet separately. Inspect connectors for looseness or visible damage. If you have a known-good compatible charger and cable, test them one at a time while keeping the other conditions the same. Avoid damaged cables or connectors.
Restart and retest. A restart can clear a stalled background task or temporary software problem. After the device is back on, let it settle, then repeat the test with the same setup.

When the charger or battery may be faulty

If charging stays slow with a compatible known-good charger and cable, at a moderate battery level, while the device is cool and idle, the issue may be with the device, its charging port or the battery. If possible, test your charger with another compatible device, or test your device with another compatible charger. A result from the browser test is not a measurement of charger wattage or a full battery health diagnosis.

Stop using a charger or cable that is frayed, unusually hot, or visibly damaged. For a device under warranty, contact the manufacturer or seller before paying for a repair. A damaged charging port or battery usually needs professional service.

Why matching conditions matters

Charging speed is not constant. Battery level, temperature, screen use and background tasks can change how quickly the percentage rises. The test reports a rate based on the battery information available to the browser, not the electrical power flowing into the battery. Use it to compare repeatable runs on the same device, not to certify a charger or compare unrelated devices.