Leaving Your Phone Plugged in Overnight

You’ve probably heard many people say how dangerous it is to leave your phone plugged in overnight. Some insist it’s bad for battery health, makes the battery wear out faster and lose efficiency quicker. But what’s really true? Does leaving your phone connected to a power source while you snooze away the best thing for your battery? Can your battery overcharge? Is it really dangerous like many people claim?

What are smartphone batteries made of?

Smartphones use rechargeable Lithium-ion (Li-ion) batteries as their source of power. These lightweight Li-ion batteries charge quicker than bigger rechargeable batteries. However, these batteries also do not retain charges for too long, mainly due to the fact that they are small and have a little capacity.

Also, many smartphone users install various apps on their devices, and these apps have a way of draining the batteries. Emails, social apps, playing music, videos and games… All of these apps take a toll on the battery. Even when these apps are not in use, many of them run in the background and slowly sucks the battery away.

Since many smartphone batteries do not last long, users often resolve to charge their phones overnight, so that they can wake up to a fully-charged phone in the morning.

So, how do these extended charging hours affect the overall battery health?

Overcharging your battery is a myth

The truth is, you can’t really overcharge your phone’s battery. Smartphones are intelligent and by design, they come with protection chips that protect the phone from accepting more charge beyond its limit. In short, once your battery hits 100%, your smartphone stops drawing in current from the charger. Most quality chargers come with this design too – they stop transmitting current once the battery is full. All of this hardware essentially prevents your phone’s battery from getting overcharged as some people often claim.

However, there’s a bad side to leaving your phone charging through the night. Although a charger stops sending charges to your phone when your phone reaches 100%, the charger continues to “trickle charge” your phone’s battery. As your battery tries to lose small charges on its own, your charger continues attempting to top off these lost charges all through the night. The downside of this trickle charging is that it keeps your battery – and by extension, your phone – hot all through the night, ultimately wearing down its capacity over time.

In fact, you do not need to fully charge Li-ion batteries for better efficiency. This is because a high voltage stresses the battery, and makes it lose charge retention capacity with each charging cycle.

What to do?

Don’t wait until your phone’s battery is fully drained to 0% before you recharge it. This is because full discharges diminish the battery capacity sooner than partial discharges.

For longer battery life, you may use your until the battery level is between 35%-40% before you recharge. It’s also important to keep your phone cool. This is because high temperatures make the battery lose its capacity faster. You may also remove your phone’s case before you plug it into a power outlet.