Why is it that your phone’s battery seems to get worse over time? At first it might have power to spare as you snuggle into bed at the end of the day, but as time goes on you find your battery is just half-full by lunchtime.

Partly it’s how you use your phone – the apps you install, the junk you collect, the customisations you make, and the more and more notifications you receive – puts more strain on the battery. (Read our tips on how to extend battery life.)

Until we have new-fangled technologies such as smart clothes that optimise wireless performance, we must learn how to charge a battery that keeps it healthy for as long as possible.

Phone batteries, like all batteries, do degrade over time, which means they are increasingly incapable of holding the same amount of power. While they should have a lifespan of between three and five years, or between 500 and 1,000 charging cycles, a three-year-old phone battery is never going to keep going as long as a brand-new battery.

Three things wear out lithium-ion batteries: number of charging cycles, temperature, and age.However, armed with our tips for best battery care practice, you can maintain your smartphone battery health much longer.

   The golden rule is to keep your battery topped up somewhere between 30% and 90% most of the time. Top it up when it drops below 50%, but unplug it before it hits 100%. For this reason, you might want to reconsider leaving it plugged in overnight.Pushing in the last charge from 80-100% causes a lithium-ion battery to age faster.Maybe it’s better to recharge in the morning instead, at the breakfast table or on your office desk. That way, it is easier to keep an eye on the battery percentage during charging.iOS users can use the Shortcuts app to set a notification when the battery level reaches a certain percentage. This is done under the tab “Automation” and then “Battery Level”.Giving your phone a full recharge is not fatal for a phone battery, and it seems almost counter-intuitive not to do so, but giving it a full recharge every time you charge it will shorten its lifespan.Likewise, at the other end of the scale, avoid allowing your phone battery to get below 20%.Lithium-ion batteries don’t feel good about going too far below the 20% mark. Instead, see the extra 20% “at the bottom” as a buffer for demanding days, but on weekdays start charging when the warning for Low Battery level appears.In short, lithium-ion batteries thrive best in the middle. Don’t get a low battery percentage, but also not too high.

   No, or at least not every time you charge it. Some people recommend that you do a full zero to 100% battery recharge (a “charge cycle”) once a month – as this re-calibrates the battery, which is a bit like restarting your computer.But others disregard this as a myth for current lithium-ion batteries in phones.To keep your long-term battery life in good health, frequent, small charges are better than full recharging.With iOS 13 and later, Optimised Battery Charging (Settings>Battery> Battery Health) is designed to reduce the wear on your battery and improve its lifespan by reducing the time your iPhone spends fully charged. When the feature is enabled, your iPhone should delay charging past 80% in certain situations, depending on Location Services that tell the phone when it is at home or work (when you are less likely to need a full charge) compared to when you are travelling.The deeper you discharge a lithium battery, the more stress is inflicted on the battery. So, topping up frequently extends battery life.

   As a rule, it’s best to avoid, despite the convenience of waking up with a full battery in the morning. Each full charge counts as a ‘cycle’, and your phone is only built to last for a set number. If you charge overnight, you are guaranteed to miss when the phone exceeds the magic 80% mark that is best for extended long-term life.While most modern smartphones have built-in sensors to shut off charging when they hit 100%, if still turned on they will lose a small amount of battery while idle.What you may get is a “trickle charge” as the charger attempts to keep the phone at 100% as your phone naturally loses on its own charge during the night. This means that your phone is constantly bouncing between a full charge and a little bit below that full charge – 99% to 100% and back again during a longer-than-required charge. It can also heat the phone up, which is also bad for the battery.So, charging during the day is better than charging overnight.Your best policy is to have Do Not Disturb and Airplane Mode switched on. Better still, you could completely switch off your phone, but that may not be possible if you rely on it as an alarm or wish to be ready to take calls at all hours. Some devices are also set to power up once the cable is connected by default. Even during waking hours, it’s best to catch your phone before it hits 100%, or at least not leave the charger supplying charge to an already full battery for too long. If you are leaving it plugged in for a long period of time, removing the case can prevent it over-heating.