Don’t charge your phone’s battery to 100%

Most smartphones today use lithium-ion batteries. These high-performance batteries have a weak point: they age faster if they are left at full charge too often. And a worn battery means less autonomy and more frequent recharging.

Battery chemistry, in a simple version

Inside, energy is stored through chemical reactions. The closer the battery is to its maximum capacity, the more the internal voltage increases… and the more the cells are stressed. Imagine a balloon that is inflated to the maximum every day: after a while, it will lose its flexibility.

Keeping the battery at 100% for a long time therefore accelerates its natural ageing.

Why aim for 80 to 90%

Studies and manufacturers’ experience show that limiting the load to around 80-90% reduces this internal stress. Result:

• Less heat generated at the end of the charge, therefore less risk of degradation.
• Less long-term chemical wear.
• Battery life that stays stable for longer.

This does not mean that you should never reach 100%. If you’re going on a trip or know you won’t have access to an outlet, a full charge is still helpful. The goal is simply to prevent it from becoming a daily habit.

Small Gestures to Extend Battery Life

• Recharge before reaching 0%
  Often going down to 0% strains the battery. Ideally, plug it in around 20%.
• Opt for partial charging A
  few minutes of charging spread out over the day is better than a long charge of up to 100%.
• Protect it from extreme
  temperatures Avoid leaving your phone in direct sunlight or in a very cold place. Both heat and cold can reduce its performance.
• Use good quality
  chargers Low-quality models can provide irregular voltage, which can damage the battery.
• Enable “optimized charging”
  On many smartphones, this feature delays the last part of charging until the usual time when you unplug the device.

The Science Behind the Practice

Manufacturers and experts agree: keeping the charge between 20 and 80% often doubles the number of full cycles a battery can withstand before its range drops.

A complete cycle means 100% of the load consumed, not necessarily at once. For example, charging from 50% to 100% is half a cycle. The fewer full cycles the battery performs, the longer it lasts.

Should we change our habits?

It all depends on your use:

• If your phone lasts 80-90%, adopt this limit.
• If you need 100% to get through the day, no problem… But avoid leaving it plugged in for long after reaching full.

The goal is to find a balance between comfort of use and battery preservation.

What you need to remember

Charging to 100% every day, especially overnight, wears out the battery faster. By keeping it between 20 and 80-90% as often as possible, you preserve its autonomy, reduce the risk of overheating and prolong its performance.

A well-maintained battery is a phone that remains efficient… and less anxiety when the icon turns orange.