Ask Jerry: Is it safe to use my phone while I'm charging it?

Welcome to Ask Jerry, where we talk about any and all the questions you might have about the smart things in your life. I'm Jerry, and I have spent the better part of my life working with tech. I have a background in engineering and R&D and have been covering Android and Google for the past 15 years.

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Using your phone while charging: Good, bad? Does it really matter?

S. asks:

The battery on my phone can't keep up with me and I need to charge it before I'm done with the day. I usually just use it while its plugged in but was told that's not a good idea. Does it really matter?

Thank you

Hiya S., and thanks for emailing in with a really good question! We all use our phones while they're plugged in at least every once in a while, so this kind of thing is really good to talk about.

The quick answer: using your phone while it's charging, especially fast charging, causes more heat to build up. Heat is bad for every part of your phone, and if it gets too hot, you'll see a warning that it's going to shut down. Honestly, though, it probably doesn't make much difference unless you're always doing it.

Having said that, it does make a difference. There are reasons why you shouldn't, as well as a few simple truths that make the whole issue not worth worrying about.

Heat is bad news

The parts inside your phone are designed to run hot, but heat is also bad for them. That sounds a little confusing, but you need to realize the difference between hot and too hot, as well as the ways your phone deals with all that heat.

Some of the parts in your phone will absolutely burn you if you come into contact with them. Electronics are like that, and the way electricity works "creates" heat, so it's not uncommon to see something like a microprocessor reach temperatures into the 75 °C range.

Your phone has a built-in method to funnel this heat away as fast as it can, though. Some phones are better than others, but every phone has passed testing so that the designers and engineers are satisfied. When you're actively using your phone, it "creates" more heat than when it's idle and the display is off.

Charging your phone also "creates" heat. I'm using quotes around the word creates because technically, it's a conversion of one type of energy into another, but "creates" is easier to understand; it makes things get hotter.

Other things your phone can and will do when it gets close to being too hot are forcing the processor and GPU to run slower, and even changing the brightness and refresh rate of the display. You might notice this, but know it's done by design to slow down the rate at which the heat is "created".

Finally, heat negatively affects the cells in your phone's battery. It lessens the battery's lifespan and capacity and eventually leads to component failure. In severe cases, it can cause a catastrophic failure, which creates something known as thermal runaway, and your phone could catch fire or explode. Thankfully, that rarely happens.

There's also the chance of mechanical damage caused by using a phone while it's plugged in. The cable port was designed to be used when the phone is in one place, and holding it can lead to the USB port connection to the main board coming loose.

In short, using your phone while you're charging it, even with a wireless charger, means it will have a shorter lifespan. But it's not as bad as you might be thinking for most of us.

You aren't keeping it forever

The extra heat caused by using a phone that's charging will make it stop working sooner. There's no question about it. But will it make enough of a difference?

Not counting your battery, which we'll talk about in a minute, the parts inside your phone will still be in fine working order when you buy a new one. If the heat and clock speeds are managed correctly (they are unless you get in there and change things, voiding the warranty), chances are the components will last for decades.

Your battery is another story, though. Plain and simple: you are either going to keep a phone long enough to need to change the battery, or you aren't. Two years is about the amount of time it takes before you start to notice your phone battery doesn't hold a charge as long as it used to, but it's measured by charging cycle and not actual time.

Starting to see what could be an issue yet? The more often you charge your phone, the shorter the lifespan of the battery will be. That's just how it is, and yes, as it gets older, you'll need to charge it more often, making its lifespan even shorter. The extra heat does have an effect here, but not a huge amount.

Ideally, you'll set your phone down and give it time to charge before you pick it back up again. Using it while you're charging now and then won't make much of a difference, but doing it all the time will mean you might end up replacing the battery or buying a new phone sooner than you had planned.