You may already have heard the warnings: Don’t overcharge your mobile phone. Make sure you unplug it from the charger after it reaches 100%. Don’t leave it charging overnight. Or else.
The direness implicit in those imperatives may be overblown, but they're not paranoid conspiracy dictums — you still shouldn't overcharge your phone. Here's why.
Mobile phones contain a rechargeable lithium-ion (or li-ion) battery. Li-ion batteries charge faster than traditional rechargeable batteries. That’s why you can plug your iPhone or Android phone into a charger, and revving it up to at least an 80% charge happens fairly quickly. But as we all know, our smartphone battery charges don’t last long. We’re often lucky to get through the day without our phones losing all their juice.
Part of that dilemma is because the batteries on our phones are relatively small and can hold only so much capacity. But the other part is due to the way we use our phones. Constantly checking email, texting people, listening to music, watching videos, using apps, playing games. All those activities eat up a single charge, causing our phone batteries to run out of gas, often sooner than expected.
So what happens if you act as I assume most do, and leave your phone plugged in overnight?
Even though a charger turns off the juice when your phone reaches 100%, the charger will continue to top off the charge during the night, says Bradshaw. Such a “trickle charge” attempts to keep it at 100% to compensate for the small bit of charge that your phone just naturally loses on its own. So your phone is constantly being bounced between a full charge and a bit below a full charge. These trickle charges can lead to higher ambient temperatures for your phone, which can reduce capacity over time.
By keeping your phone charged overnight, you’re actually increasing the amount of time your device spends with the charger, thereby degrading its capacity that much sooner.
What charging advice do experts have for smartphone owners?
Don’t wait until your phone gets close to a 0% battery charge until you recharge it, advises Cadex’s Bradshaw. Full discharges wear out the battery sooner than do partial discharges. Bradshaw recommends that you wait until your phone gets down to around a 35% or 40% charge and then plug it into a charger. That will help preserve the capacity of the battery. You should also keep your phone cool, as higher temperatures accelerate the loss of battery capacity. Pro tip: Take off your phone’s case before you charge it.
Full Story- Why You Shouldn't Charge Your Phone Overnight