Tech expert shares what really happens if you charge phone overnight

If you're in the habit of charging your phone overnight or unplugging it the moment it hits 100% to 'save the battery',tech gurus have some news for you: there's no need to scramble for the off switch when your phone is fully charged, as it doesn't affect theoverall health of the battery.

This insight emerged after a Reddit user posed the question: "Is it really that bad to overcharge your phone / charge it overnight? Every time I search it, I get a lot of answers - some suggest that it is bad for the battery, and others saying that there is no problem. Now I'm confused."

In response, a tech whizz commented: "It doesn't overcharge, and you don't need to baby it. Just plug it in when you feel like it and leave it plugged in as long as you want, the charging controller will take care of the battery."

They added advice for iPhone users: "If you have an iPhone, leave Optimized Charging turned on and only turn it off temporarily if you know you want 100% before going on a hike or whatever. Batteries are consumable though, no way around it. It would lose capacity over time even if you didn't use/charge cycle it at all."

Echoing this sentiment, another expert concurred: "The other commenter is 100% correct. Modern phones & chargers are smart enough to slow the charging down and then stop it as the battery gets full, so you don't have to worry about it at all."

A user advised on battery care, saying: "Don't worry about it. The only thing to avoid really would be getting your battery down to under 20-30% frequently especially if it gets hot (mobile gaming) and then wireless charging immediately after while it's still hot."

They added a cautionary note about heat and battery depletion: "Heat isn't good for batteries, nor is cycling down to very low %s. Other than that don't worry much."

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Apple Support has provided guidance for iPhone users looking to extend their battery life with the 'charge limit' feature, stating: "With iPhone 15 models and later, if the charge limit is 100 per cent, you can also turn on Optimised Battery Charging. Your iPhone has these settings by default."

The statement continued to explain the charging process: "Your iPhone will charge to within a few percentage points of your chosen limit and then stop charging."

It further detailed: "If the battery charge level drops more than 5 per cent while connected to power, charging will resume, again charging to within a few points of your chosen limit."

Apple Support also mentioned that iOS may offer recommendations based on usage patterns: "If iOS determines that a charge limit will help preserve your battery's lifespan, you'll see a recommendation."

An example was given: "For example, you may see 'Based on your iPhone habits, a charge limit of 95% is recommended to help preserve your battery'."

Instructions were provided for adjusting the 'charge limit' on newer iPhone models: You can change your 'charge limit' on iPhones 15 models and later by going to Go to Settings > Battery > Charging.

The final details included the range of charge limits available and the option for Optimised Battery Charging: From here, you can choose a charge limit between 80 per cent and 100 per cent in 5 per cent increments. When the charge limit is 100 per cent, Optimised Battery Charging is available.

For iPhone 14 owners and those with older models, navigate to Settings > Battery > Battery Health & Charging.

From there, you can switch Optimised Battery Charging on or off. Disabling charging optimisations may accelerate battery deterioration and shorten its overall lifespan.

Nevertheless, Laurie Pollard, managing director of Firechief Global, has cautioned people to stay alert to the fire risks that come with charging mobiles whilst in bed.

He explained: "Phones generate heat during charging, and covering them with pillows or blankets can trap that heat, increasing the risk of overheating and potentially causing a fire."

He emphasised the need to charge devices on clear, level surfaces well away from combustible items to reduce these dangers - and cautioned against overcharging gadgets, describing it as a primary trigger for blazes in equipment containing lithium-ion batteries.