Phone and laptop battery care: what really helps and what is a myth

What actually helps

• Avoid heat. Heat is the biggest enemy of a lithium-ion battery. Apple says its devices are most comfortable at an ambient temperature of 16 to 22 degrees, and that ambient temperatures above 35 degrees can permanently reduce battery capacity. Do not leave a phone on a car dashboard, in direct sun or on a radiator.
• Take some cases off when charging. Apple notes that charging in certain cases can generate excess heat. If your device gets hot while charging, remove the case.
• Do not game or stream heavily while charging if the device is getting hot. Charging and heavy use together produce a lot of heat.
• Let the device manage charging. Most modern phones and many laptops have a setting that learns your routine and delays charging past around 80 percent until you need it, or lets you cap the charge. Apple calls this Optimised Battery Charging. Samsung, Google and many laptop makers have their own versions. Turning this on is the easiest win.
• Store devices half charged. If you will not use a device for a while, Apple recommends storing it at around 50 percent, somewhere cool and dry, and topping it up to about 50 percent every six months. Storing a battery completely flat risks a deep discharge that can stop it holding charge at all, and storing at 100 percent for a long time reduces capacity.
• Use a good charger. Use the charger that came with the device or one from a reputable brand that meets the right standards. Cheap uncertified chargers are a safety risk, not just a battery-health one.
• Keep the software updated. Updates often include battery management improvements.

Myths you can stop worrying about

• Myth: you must drain the battery to zero before charging. That was true of older nickel-based batteries with a memory effect. Lithium-ion batteries do not have it. Topping up whenever is fine, and regularly running to zero is worse for them.
• Myth: charging overnight will overcharge and ruin it. Modern devices stop charging when full. Optimised charging features also reduce the time spent at 100 percent.
• Myth: you must charge a new phone for hours before first use. Not needed for lithium-ion.
• Myth: fast charging destroys batteries. Devices manage fast charging, slowing it as the battery fills and as it heats up. Heat is still the thing to watch.
• Myth: closing all your apps saves battery. On modern phones, apps in the background are usually suspended. Force-closing them and reopening them can use more energy than leaving them. Close an app only if it is misbehaving.
• Myth: cold destroys batteries. Cold reduces performance temporarily, and a phone may shut down in freezing weather, but the battery generally recovers once warm. Heat causes lasting damage.

Making a charge last the day

• Lower the screen brightness or use auto brightness. The screen is often the biggest drain.
• Use dark mode if your phone has an OLED screen.
• Check which apps use the most battery in the battery settings and restrict background activity for the worst offenders.
• Turn on low power mode when you need to stretch the charge.
• Poor signal drains battery. In an area with weak mobile signal, use wifi where possible.

Laptops specifically

• Many laptops have a battery health or charge limit setting in the maker's app or system settings. If your laptop is plugged in most of the time, turning this on is worthwhile.
• Keep vents clear. Using a laptop on a duvet blocks airflow and heats both the processor and the battery.
• Do not leave it in a hot car or sunny window.

Know when to replace it