Can I Leave my iPhone Charging Overnight? does this will affect the battery life in the long run??

Yes, it is absolutely find to leave your phone on charge overnight. In fact, it's best practice. If your phone is plugged in, the screen is locked and the phone is connected to WiFi, it will back up every night (assuming you have iCloud back up enabled) and be fully charged and ready to go in the morning.

You can't overcharge modern lithium ion batteries. Once the battery reaches full charge, it stops charging. You will not "burn out" the battery by leaving it on a charger.

miss.manson. wrote:

Ideally, you would only charge your phone when the battery is almost empty and then allow the battery to completely charge before disconnecting.

This is the worst possible thing you can do to a lithium chemistry battery. It will shorten its life considerably.

Depending on the iPhone you have, your phone may have the capability to stop receiving a charge once the battery is fully charged. If you have an older iPhone, however, you may be better off charging while you're awake and can unplug it once it becomes charged so as not to burn out the battery so quickly. Ideally, you would only charge your phone when the battery is almost empty and then allow the battery to completely charge before disconnecting.

miss.manson. wrote:

Depending on the iPhone you have, your phone may have the capability to stop receiving a charge once the battery is fully charged. If you have an older iPhone, however, you may be better off charging while you're awake and can unplug it once it becomes charged so as not to burn out the battery so quickly. Ideally, you would only charge your phone when the battery is almost empty and then allow the battery to completely charge before disconnecting.

Untrue and unnecessary for any lithium battery manufactured in the last 20 or so years and made to global industry SMART standards. Apple itself has never sold a single lithium battery powered product that could be over charged. They have always used industry standard batteries and those very standards require every consumer product lithium battery to include built in over charge protection.

And deep discharge cycles will actually degrade a lithium battery faster than more shallow discharge cycles and more frequent charging will.

Your recommendation would only make any sense if using much older battery technology such as NiMH.