Low Power Mode slows charging down, not speeds it up

Low Power Mode does not make your phone charge faster. In fact, it typically slows charging slightly because the phone is using less power overall — which means the charger has to work less hard to keep up with what the battery is losing to background processes. The confusion comes from mixing up two different things: how fast the battery fills, and how long the charge lasts once it's full.

What Low Power Mode actually does is reduce the rate at which your phone drains power while it sits idle or while you use it. If your phone is losing power more slowly, a charger of the same wattage will take longer to fill the battery completely, because the phone is consuming some of that incoming power as it charges. The charging speed itself — measured in watts delivered to the battery — does not change.

Key Takeaways

  • Low Power Mode reduces how fast your phone uses power, which can make charging appear slower because the phone consumes some incoming power while charging.
  • The actual charging speed in watts does not change when you turn on Low Power Mode.
  • Charging speed is determined by your charger's wattage and your phone's hardware, not by software settings.
  • To charge as fast as possible, turn off Low Power Mode and use the highest-wattage charger your phone supports.
  • Turning on Low Power Mode after the phone is fully charged will extend how long that charge lasts.

What actually controls how fast your phone charges

Charging speed depends on two things: the wattage of your charger and the maximum wattage your phone's battery can accept. An iPhone 15 with a 20-watt charger will charge at roughly 20 watts. The same phone with a 30-watt charger will still charge at roughly 20 watts, because the phone's hardware caps it there. A Samsung Galaxy S24 with a 25-watt charger will charge faster than the iPhone because Samsung's hardware accepts more power.

Low Power Mode is a software setting that tells your phone to use less power for background tasks, screen brightness, and processing speed. It does not change how much power the charger sends to the battery. The phone will still accept the same amount of incoming power — it just uses less power for other things while charging happens.

If you want to charge faster, use the highest-wattage charger your phone supports and turn off Low Power Mode. If you want your charge to last longer after it reaches 100 percent, turn on Low Power Mode once charging is complete.

Why Low Power Mode might make charging feel slower

When Low Power Mode is on, your phone uses less power overall. This means the charger's power is split between filling the battery and running the phone's basic functions. If your phone is using 2 watts to stay on and respond to notifications, and your charger is sending 20 watts, only 18 watts go directly to the battery. With Low Power Mode off, more of that 20 watts goes straight to the battery.

The difference is usually small — a few minutes over a full charge cycle — but it is real. The effect is more noticeable on slower chargers. A 5-watt charger will show a bigger difference than a 20-watt charger, because the phone's background power use becomes a larger percentage of the total incoming power.

How to charge your phone as quickly as possible

Turn off Low Power Mode before you plug in. Use the charger that came with your phone, or a third-party charger rated for the same or higher wattage. Check your phone's settings to confirm the maximum wattage it supports — this information is usually in Settings under Battery or Power.

Keep your phone cool while charging. Heat slows down charging speed and damages battery health over time. If your phone gets warm, remove any thick case, move it away from direct sunlight, and avoid using it while it charges. Wireless chargers generate more heat than wired chargers, so wired charging is faster.

Close apps running in the background, though the effect on charging speed is minimal. The bigger factor is the charger itself — a 30-watt charger will always beat a 5-watt charger, regardless of what apps are open.

When to use Low Power Mode during charging

Use Low Power Mode after your phone reaches 100 percent, not before. Once the battery is full, Low Power Mode will extend how long that charge lasts by reducing background power drain. This is useful if you know you will not have access to a charger for several hours.

Some phones, like recent iPhones, also offer Optimized Battery Charging, which slows charging to 80 percent and then pauses until you need the phone. This protects long-term battery health by reducing the time the battery spends at 100 percent. You can turn this on or off in Settings under Battery Health.

Charging speed differences between phone models

Different phones charge at different maximum speeds. iPhones typically max out between 20 and 30 watts depending on the model. Samsung Galaxy phones often support 25 to 45 watts. Google Pixel phones support 20 to 30 watts. These limits are built into the phone's hardware and cannot be changed by software.

Older phones charge more slowly than newer ones, even with the same charger. A 2019 iPhone will not charge as fast as a 2024 iPhone, because the older battery hardware does not support higher wattages. If you upgrade your charger but your phone is several years old, you may not see much improvement.

Frequently Asked Questions

Does Low Power Mode damage my battery if I charge with it on?

No. Low Power Mode is a software setting that does not harm the battery. Charging with Low Power Mode on is safe — it just takes slightly longer. Heat is what damages batteries over time, so keeping your phone cool during charging matters more than whether Low Power Mode is on.

Will a faster charger damage my phone?

No, as long as the charger is rated for your phone's voltage and connector type. Your phone's hardware will only accept the maximum wattage it supports, so a 65-watt charger will not overcharge a phone that maxes out at 20 watts. The extra capacity simply goes unused.

Why does my phone charge slower than it used to?

Battery capacity decreases over time, which can make charging appear slower. A degraded battery may also trigger thermal throttling, where the phone slows charging to prevent overheating. Check your battery health in Settings under Battery or Power. If it is below 80 percent, the battery may need replacement.

Can I charge my phone overnight without hurting the battery?

Yes, modern phones are designed to handle overnight charging safely. Once the battery reaches 100 percent, the charger stops sending power. Some phones offer Optimized Battery Charging, which pauses charging at 80 percent until you need the phone, and this can extend battery lifespan if you charge overnight regularly.

Does airplane mode make charging faster?

Slightly, because the phone uses less power for cellular and wireless connections. The effect is smaller than turning off Low Power Mode, and most people will not notice the difference. If charging speed matters, use a higher-wattage charger instead.