Do iPhones charge slower when in low battery mode?

Absolutely not.

How fast your battery charges is actually quite simple. Think of the power as water and your phone as a bucket with a faucet. Like this one:

How fast that bucket will fill with water when you start filling it will depend on how fast the water is going in and how fast it is going out. Same with the iPhone. When you are charging it and using it at the same time, you are adding power and using it at the same time. Most of the time, the power coming in will be greater than that going out. If you reduce power, it will charge faster. The fastest possible way to charge your phone is to put it into Airplane Mode and turn off the screen. However, low power mode is almost as good and it will charge far faster in low power mode than in regular mode.

Whoever you heard that from was not only wrong, but told you the complete opposite of the truth.

Of course not, the iPhone charger does not charge the iPhone slow in Low Battery Mode or when the battery is low. Probably the reason behind slow charging is usually the apps active and running in background. There are broadly only 2 factors behind slow charging. One is apps running in background and using the device while charging as the screen is on.

If you want your phone to get charge faster do following things :-

1. Switch off the location services or at least make efficient use of location services by allowing only limited apps.
2. Close all background running apps.
3. Always charge your phone when your battery percentage is ranging from 20% t0 85%. Do not over charge or completely drain your device it will increase battery life as well.
4. If possible, put your phone on Airplane mode for 30 minutes to get the boost charge.

Happy to help, hit upvote!

According to that theory, the phone shouldn’t charge at all, while it is turned off.

Everything is “off”, how come it is charging? :)

No?

Yes!

This may not be in relation to your question but just a tip! If you get a "Low battery" message, that only means you should charge right away but what if there are no power cords to charge your phone? A great traveler should always be ready, as I am one! That’s why I’m sharing with you the best power banks!!!! Read carefully as these power banks have some reviews given by their users.

//Riza

Phones charge slowly for any of these reasons:

• You are using the phone. The phone will draw current in itself and slow down charging speed. This is more significant if you have an Android device with fast chatging. The phone will charge at 5V instead of 9V and lower current
• You are using a low quality USB cable that cannot handle much current
• You are using a low quality wall adaptor that does not supply much current. They can also damage your phone as they lack protection circuitry which stops surges and smoothes out the output.

Low power mode will never slow down charging.

No it doesn't.
Low battery mode means

• it switches all the apps to go for background uses
• it switches all Bluetooth and WiFi off
• it lower the brightness level
• also even it reduces the resolution for higher battery performance.

So whenever you plug in charger it charges as usual. there is nothing to do with low power mode.