How to charge your cellphone battery, the right way


Angela Mulholland

Charging a cellphone sounds simple, right? When it runs out of power, you plug it in until it’s charged back up.

But according to the battery experts at, a website created by Cadex Electronics, that’s the wrong way to do it if you want to extend your phone’s battery life.

Here are their tips along with a few from the big phone makers.

Most cellphones these days (as well as most tablets, cameras, golf carts and a ton of other devices) use rechargeable lithium-ion batteries, otherwise known as Li-ion. Unlike the old nickel cadmium batteries, Li-ions are not prone to the “memory effect” in which the battery “forgets” how to hold a full charge unless it is “taught” how by regularly draining it completely, before recharging it back up to 100 per cent.

That means your phone doesn’t need to be fully drained before you plug it in. In fact…

Don’t let it run dry

Fully draining your phone’s battery is never a good idea, because recharging it back up from that level causes high stress on the battery. The experts at Battery University say it’s really best to not let the battery run down below 25 per cent at all.

The worst habit of all. though, is to run the battery completely and then charge it back up to 100 per cent in one go. That causes “undue stress,” say the experts, and will eventually shorten the battery’s lifespan.

But don’t leave it fully charged either

Strangely, our phone batteries don’t like to sit idle when they’re charged to 100 per cent, either. The experts at Battery University say a Li-ion’s “sweet spot” is a charge of somewhere between 30 and 80 per cent.

So, unplug the charger before the battery is fully charged, and definitely don’t leave it charging all day or night, since that will leave it at 100 per cent for too long.

Of course, you won’t kill the battery by doing this from time to time, but we’re talking about the ideal way to get the longest life from it.

Keeping the battery in the “sweet spot” might mean plugging it in a couple of times a day, especially if you use the device compulsively. But when you do charge it up, Blackberry says to make sure it’s a long charge, since they recommend against “small increment” boosts of 15 minutes or less.

Keep it cool

Cellphones perform best at room temperature. As any Canadian who has used a phone in the winter knows, the battery drains quickly in the cold.

But what’s even worse for the battery is heat. Never leave a phone (or any electronic device) where temperatures could go higher than 35 degrees Celsius, such as a hot car. Doing so can permanently damage the battery, making it less able to hold a charge from then on.

Keep it updated

Apple, BlackBerry and Android all recommend users have the latest version of their operating systems, since these updates often include “advanced energy-saving technologies.”

Keep it partially charged when storing

If you’re planning to put your phone away for a while, instead of draining the battery, charge it to 50 per cent and then turn it off. Apple says if you run out the battery before storing the device, the battery could fall into “a deep discharge state,” which would make it then unable to take a charge at all.

Tips for extending battery life

Closing all the running apps on your phone probably won’t do much to save the battery, but here are a few things that will:

• Use Wi-Fi instead of a cell network whenever possible

• Keep your screen as dim as possible

• Avoid animated or live wallpaper

• Turn off your phone’s keyboard sounds and vibrations in settings

• Set your screen’s Timeout or Sleep mode to turn off the screen after 30 or even 15 seconds of no use

• Turn off Bluetooth and Wi-fi when not in use

Drew Sauveur
Author: Drew Sauveur

Local business owner and resident of Durham Region

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