Why charging your phone to 100% might be doing more harm than good

In the age of smarter devices, it turns out we need to get smarter about how we charge them too. If you're still plugging in your phone overnight and waking up to a 100 per cent battery every morning, tech experts say it's time to rethink your routine. Why? Because charging your phone all the way to 100 per cent — or letting it drain to 0 per cent — could be silently shortening its battery lifespan. The heart of your smartphone — its lithium-ion battery — is a delicate piece of technology. These batteries don’t respond well to extremes. In fact, research and real-world usage both show that keeping your phone’s charge level between 20 per cent and 80 per cent is ideal for long-term health.

Why 100 per cent isn’t ideal, and 0 per cent is even worse

Here’s what’s happening behind the scenes: when you push your battery to full capacity or let it drop to empty, the chemical reactions inside the battery become more stressful, which leads to faster wear and tear. Over time, this can reduce the battery’s ability to hold a charge — meaning your once-long-lasting phone might start dying before lunchtime. Think of it like stretching a rubber band to its maximum limit over and over again. Eventually, it loses its elasticity. The same concept applies to lithium-ion cells.

Simple tricks to preserve battery life

The good news? You don’t need to hover over your phone all day to manually stop charging at 80 per cent. A host of smart apps and features now do the work for you.

• AccuBattery (Android): Monitors charge cycles and alerts you to unplug at your desired percentage.

• Battery Guru (Android): Offers in-depth stats on charging habits and battery health.

• Charge Limiter (Android, root required): Lets you set custom charging thresholds.

• iOS Optimised Battery Charging (Built-in): iPhones have a native feature that learns your daily charging routine and slows charging at 80 per cent until you need it fully.

Most modern Android phones also have ‘Battery Protection’ or ‘Adaptive Charging’ options under battery settings, allowing you to cap charging or slow it down overnight. If you absolutely must charge overnight, ensure your phone has features like optimised charging switched on.

These features pause charging at around 80 per cent and top it off slowly just before you wake up, reducing the battery stress. Your phone’s battery isn’t designed to last forever — but with the right habits, you can slow its decline. Sticking to the 20-80 rule, avoiding extreme temperatures, and making use of smart charging tools can keep your phone healthier, longer.