(NEXSTAR) – Though it has been around for a few months, a new feature is causing some iPhone users to report slow charging times. But have no fear, you can turn it off.

When Apple announced a new iOS update last fall, some users were excited to see new features like the ability to edit text messages after they had been sent and lock screen customizations.

Some, however, seem to have overlooked Apple’s new Clean Energy Charging feature designed to reduce your phone’s carbon footprint “by optimizing charging times for when the grid is using cleaner energy sources,” the company says.

Users on Reddit and TikTok have been reporting slow charging times in recent weeks, blaming the Clean Energy Charging feature.

“I learned about it because I could only charge my phone for two hours this morning and couldn’t figure out why my phone had no charge afterward,” Tim Latimer, CEO of Fervo Energy wrote on Twitter Sunday in a thread criticizing Apple for a lack of transparency regarding the feature.

When Clean Energy Charging is enabled — by default, it’s automatically turned on following the iOS 16.1 update released in October, or if you buy a new iPhone — Apple explains your phone will receive “a forecast of the carbon emissions in your local energy grid and uses it to charge your iPhone during times of cleaner energy production.”

This means that, during times when electrical use is high, or if you live in an area that relies more on higher carbon emission electricity, your phone’s charging may be slowed.

According to Apple, Clean Energy Charging works with another feature, Optimized Battery Charging, “to learn your charging habits.” The Clean Energy Charging will only kick in “where you spend the most time and regularly charge your iPhone for long periods of time.” The feature won’t impact you while you’re traveling, for example, or if you’re in a new location.

If Clean Energy Charging does stop your phone from charging, Apple says a notification will appear on your lock screen explaining when your phone will be fully charged (you may see a similar notification if you already use Optimized Battery Charging). You are able to touch and hold that notification and tap ‘Charge Now’ if you need your phone fully charged sooner.

You can also completely turn the feature off.

On your iPhone, head to Settings, then Battery, then Battery Health & Charging. Once there, you’ll see the toggle next to Clean Energy Charging: if it’s green, tap to turn it off.

If Clean Energy Charging isn’t turned on, and you’d like to opt in, you can tap the toggle to activate the feature. Apple notes other settings may need to be turned on to use Clean Energy Charging, including location services, system services, and significant locations.

You can find more details on Apple’s website, or under the Battery Health & Charging section on your iPhone.

There may be other reasons your iPhone is charging slowly, too. For example, you may have an older model, the charging cable may be damaged, or your phone became too warm while charging.

Alix Martichoux contributed to this report.