Charging your phone overnight might feel like a handy habit, but tech experts suggest it’s best avoided. Major Android manufacturers, such as Huawei, warn users against leaving their devices plugged in for prolonged periods, especially overnight.

The ideal approach is to charge your phone during the day, following guidelines to prolong battery life by preventing extreme levels—never letting the charge exceed 70% or drop below 30%.

Apple users can take advantage of battery optimization settings, which activate below 80% to preserve battery health.

Most modern cellphones are powered by lithium-ion batteries, which naturally degrade over time. This process occurs because of the constant movement of charge carriers between electrodes during charging and discharging. Charging your phone while you sleep extends the time it remains plugged in, putting additional strain on the battery.

This prolonged exposure causes an accumulation of a substance known as the solid electrolyte interface (S.E.I.). To picture this, imagine trying to overfill a sponge with water—it eventually starts to wear down and lose absorbency. A similar effect takes place in your phone battery, impacting its overall capacity and longevity.

Allowing the battery to discharge down to zero percent, though it may feel counterintuitive, can actually benefit battery health. This practice lowers stress on the electrodes, which helps maintain the battery’s capacity over the long term. Another essential consideration is safety.

Charging a phone overnight, particularly if left on a soft surface such as a pillow or blanket, can pose a hazard due to the risk of thermal runaway. When a battery’s temperature rises without being noticed, it could potentially lead to overheating or even fire hazards. Paul Shaw, a member of Staffordshire Fire Rescue, cautions that phone fires are often the result of unnoticed temperature increases while people sleep. Ensuring safe charging practices, like keeping your phone on a hard surface or nightstand, is a simple but crucial step in preventing such risks.

Your daily charging habits play a big role in the overall health of your phone’s battery. Avoid charging for extended periods after the device has reached 100% as this can wear down the battery faster. Apple’s Optimized Battery Charging feature is designed to help with this by learning your charging patterns and then pausing at 80% before resuming to full charge just before you typically start using the phone again. Balancing both the lifespan of the battery and the amount of time between charges requires adopting a mindful approach to charging routines, which will help ensure that the battery maintains its maximum potential over time.