People who know me as a tech tester are often very confused when discovering what charging speed I tend to use.
Despite owning a phone that powers at 80W, and having tested mobiles that go up to 150W, my go-to charger powers at a blazing 2.75W.
I used to be in the camp that believes fast charging is better than a big battery, and I still appreciate a mobile phone that powers up in seconds. When I’m reviewing a fast-charging device, I’ll invariably be pleased.
But with my own mobile, I take things slow. The more I’ve covered tech, the more I’ve begun to measure and understand a phone’s charging speed, and it’s really helped me learn how to protect a phone’s longevity.
Most people who’ve owned a phone know that its battery life diminishes over time. It might begin by lasting days, but after a few years of use, you’ll be lucky to see it last until lunchtime.
Due to the nature of the tech, charging speed directly impacts it. So, to keep my handset ticking much longer, I began using the slowest charger I own, and I always tell others to do the same.
I stopped buying random chargers after learning how they actually work
This is what actually matters when buying a new charger
How to charge your phone frugally
Setting the record straight
Let’s get some facts straight about how charging your phone works, so we’re all speaking the same language.
Imagine your phone’s battery is like a red solo cup. When you charge, you fill it with a drink, up to 100%, which you can enjoy at your leisure.
But this red solo cup isn’t infinitely refillable. Every time you use it, a little bit of sediment remains, reducing how much liquid can fit in the cup by small amounts.
It’s barely noticeable in the beginning, but over multiple refills over several years, the amount of sediment increases until you’re not getting much in your red solo cup, and finishing your drink is remarkably quick.
That’s basically how battery health works in a phone, or any lithium battery: the more you reuse it, the less capacity it can hold (it’s not a perfect metaphor, as expert readers will no doubt have picked up, but it’s a useful way of explaining the concept).
However, in batteries, unlike the metaphorical red solo cups, there are ways to increase or decrease this drain.
Experts generally recommend keeping your phone between 20% and 80% charged, as this reduces stress on the battery from too little or too much charge, though some recommend powering up your phone to full at least once a month.
Generally, though, keeping your phone plugged in while at 100% is frowned upon. This process can speed up battery degradation in the long run. So, avoiding that is paramount for battery health.
This is a problem if you have a fast charger or like to plug in your mobile overnight. These can increase the time you’re at 100%, and harm the battery health, and that’s what my charger switch is all about.
Why I have a super-slow cable
And I mean super slow
For a hiking trip several years ago, I bought a modern-day Nokia feature phone. It has the long battery life and bare-bones connectivity that would serve me well for a week off-grid, but a few modern trappings like USB-C charging.
The charger that came in the box may have been USB-C, but its charging speed is a leisurely 2.75W. It’s fine for a feature phone with a tiny battery, but it’s ludicrously slow for any other kind of gadget.
When I first took this sloth-like USB-C charger out of the box, I laughed it off as a novelty and put it to one side.
But months later, when the hike was in the rear-view mirror, I was brainstorming ways to keep my phone’s battery lasting longer, and I remembered this slow charger. I plugged it in next to my bed, and it’s remained there to this day.
Slow-charger powering speeds
How slow is ‘slow’?
Nowadays, I don’t just use this USB-C charger for my smartphone. I use it for headphones and tablets, too. I’d use it for my laptop, but it’s not actually fast enough to change the power percentage.
If my phone’s on a low percentage, I can plug it in overnight, and by the morning, I’ll be at full, but just at full, with no hours of overcharging hurting the battery.
I know it only tickles along to full right before wake-up because I’m often awake before my alarm and catch it in the high 90% range.
My iPad takes more than a night to power back to full with this charger. So, I have no worries about leaving that connected for ages. Just right, too, given how poor iPad battery lives can be at the best of times.
It’s not always a popular accessory. My partner has, during the day, accidentally used my slow charger instead of her own “normal” one, and been unimpressed by how little charge it provided.
An hour of powering can see about 10% gain, and sometimes even less if the handset is in use.
Some phone charging time estimates can be confused by how plodding the charging can be, which is a shame because I love this feature.
I’ll admit that from time to time during the day, I’ll use a fast charger to get a little extra power.
Slow charging may be the best way to go
By the nature of things, it’s impossible to tell whether my slow-charging habits have made a significant improvement to a phone’s battery life.
It’d be hard to tell without using two of the same device identically over several years, and only charging them in different ways.
But plenty of my older phones still perform great, so I’d like to believe it’s helped, and I’ve never felt any of my devices get too warm when powering up. And at the very least, it’s helped me get into healthy and regular charging routines.
I’m not the only person who’s made the change. Plenty of people are content with slow charging for other reasons.
