Over the years, the components inside our gadgets grew smaller and more powerful. In turn, tablets, phones, and laptops became sleeker and faster. What hasn’t changed, however, is the battery that powers all our gadgets. Lithium ion has long been the rechargeable battery of choice for portable electronics, from an Android tablet, to the iPhone, to all manner of laptop.
Lithium-ion (also referred to as Li-ion) batteries are prized for their ability to charge quickly and run for a good amount of time before losing their charge. Plus, they have a high power density, meaning they can pack lots of life into a small package.
A variant of the lithium-ion battery is the lithium-ion polymer (also referred to as a lithium polymer or, more simply, a li-poly or LiPo). In simple terms, it’s a lithium-ion battery in a soft pouch, which gives manufacturers greater design flexibility. For the purposes of our discussion, there’s no difference between lithium-ion and lithium-polymer batteries; the best practices for one apply to the other.
Life vs. Span
Before we dive in, allow us a brief comment on battery life versus battery lifespan. To be clear, we are discussing the latter, which refers to battery performance over the entire life of your device. In contrast, battery life refers to the amount of time your device runs on a single charge. If you have owned any type of mobile device then you have almost assuredly noticed that batteries don’t work as well as they used to over time. Perhaps right out of the box your phone ran all day and into the night, but two years down the road it has you scrambling to a wall outlet by lunchtime.
A lithium-ion battery has only so many discharge/charge cycles before its performance diminishes. By following a handful of best practices, you can extend the lifespan of your battery. Or, more accurately stated, slow its decline. And because so many mobile devices including the iPad feature designs that make it difficult or costly to replace the battery, it’s doubly important to know how best to care of it.
Forget the “Memory Effect”
If you have been told to charge a new device and let it run down completely so it remembers what its full capacity is, then there’s a bridge in Brooklyn we’d like to sell you.
Before the era of the lithium ion, most batteries were nickel-based. Devices with nickel-cadmium or nickel-metal-hydride batteries needed periodic full discharges to calibrate their full capacities. The memory effect, however, doesn’t apply to lithium-ion batteries.
Charge Quickly, Charge Often
There are, of course, some rules that apply to lithium-ion batteries to aid their longevity. A full discharge isn’t necessary and is among the worst things you can do. According to Battery University, lithium-ion batteries will last longer if you perform more frequent shallow charges. Similar to human health, it’s better to run a few miles a day than it is to rest up all month, jump out of bed, and run a marathon.
Some devices charge quickly to a point and then slowly charge the rest of the way to a full charge. The iPhone, for example, charges quickly up to 80% capacity and then trickle charges the rest of the way to 100%, which it says “eases the electrical current to extend battery lifespan.”
So, why not take advantage of the quick charge capability of a devices and perform more frequent quick charges? That is, plug in your tablet or phone when you aren’t using it and are near an outlet. As for your laptop, plug it in when not in use or when you are using it and it’s not uncomfortable to have the power cord connected. The point isn’t to charge fully to 100 percent every time but to simply to charge it when you can.
The results of Battery University’s testing reveals that frequent shallow charging is beneficial to a battery’s overall health and lifespan, but a simpler conclusion can be drawn about the benefits of frequent charges. But first, a quick note on charge cycles:
A battery has only a certain number of charge cycles before performance begins to decline. Apple, for example, estimates that an iPhone’s battery loses 20% of its original capacity after 500 complete charge cycles, while an iPad or a MacBook loses 20% after 1,000 charge cycles.
And just what exactly constitutes a complete charge cycle? You complete one charge cycle after you have used up an amount that equals the full capacity of your battery, which can happen over multiple days and charges. For example, you could use 60% of your battery today, fully charge it overnight, and then use 40% tomorrow. That’s a complete charge cycle.
Now, back to our simple conclusion about frequent shallow charges. It boils down to this: When you are charging a device, you aren’t draining its battery, which prolongs your current charge cycle.
Of course, you can simply turn off your tablet, phone, or laptop when not in use to prevent needlessly draining your battery, but if you are as lazy and impatient as the rest of us, then you don’t wait for it to turn back on from a fully powered-down state.
If you do need to take a break from your tablet to curb a bad Netflix habit or are just going on vacation for a few weeks without your laptop, then you should try to get the battery to about 50% capacity before shutting it down.
“If you store a device when its battery is fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge. Conversely, if you store it fully charged for an extended period of time, the battery may lose some capacity, leading to shorter battery life,” Apple writes.
Stay Out of the Kitchen
Whether you’re putting a device in long-term storage or using it every minute of every day, one of the most important rules to follow — if not the most important — is to avoid extreme temperatures. There is nothing worse for a battery’s long-term health than heat.
According to Apple, the ideal temperature zone for its products is between 62 and 72 degrees F. That’s all well and good, but unless you winter in Arizona and summer in San Francisco, you and your tablet or phone will find yourselves outside that comfortable zone throughout the year. Apple also states that its products work best between 32 degrees F and 95 degrees F, while Samsung is a bit more lenient in its phone guidelines (PDF), suggesting you avoid temperatures below 32 degrees F and above 113 degrees F. The higher numbers are more important to remember because extreme heat can permanently damage battery capacity while extreme cold only temporarily decreases battery life.
Even on blazingly hot days we need our tablets, so in such situations keep your device out of direct sunlight as much as possible. That is, don’t leave it lying on your towel in the sun at the beach but keep it under your umbrella. And don’t leave it locked in a hot car. Treat your tablet on a hot day as you would your dog.
And some phone cases are so bulky and protective that they don’t let the device breathe properly. If your phone runs hot in your case, take it off while charging.
A Word on Chargers
In many cases,, the best advice is to use the manufacturer’s charger and avoid third-party brands. That isn’t to say this is the only option, but it an easy one.
You want to make sure that the voltage of a charger matches the specifications of your device, which you can be assured of when using the charger that it shipped with.
If you lost your charger want an inexpensive backup, choose a one from a company that is certified by your device’s manufacturer. For example, you’ll see many chargers from Belkin and Mophie in the Apple Store, which means they’ll work just fine with your iPad or iPhone. What you want to avoid are knockoffs you might stumble across on Amazon with too-good-to-be-true prices or the cheap and colorful chargers that catch your eye at the checkout counter at CVS.
It’s also best to avoid the allure of wireless chargers, which can heat batteries and shorten their lifespans.
It’s perfectly fine, however, to keep your device plugged in after the battery is fully charged. Chargers these days are smart enough to stop sending current to the battery once it has reached full capacity.
That’s not to say you need a $200 alarm clock. As CNET found out directly from an Apple Store Genius, it’s a good idea to give your phone a break from time to time. Your battery will last longer if you power your phone off at night instead of leaving it running and charging while you sleep only so that its alarm will get you out of bed. A sound investment in a cheap alarm clock will help your phone or tablet live a longer, happier life.
Longer Life, Longer Lifespan
If we use Apple’s guidelines on an iPhone’s charge cycles, we can come up with a working estimate of how long your phone or tablet battery will run at close to its full capacity before it begins to lose its luster. Apple says an iPhone is designed retain up to 80% of its original capacity after 500 charge cycles.
Let’s say you use 75% of the battery each day on average. That would mean it would take you 667 days to reach 500 charge cycles — or roughly one year and 10 months. Or likely two months before your contract is up and a phone upgrade becomes reasonably priced. The important thing to remember is that after those 22 months, your iPhone’s battery isn’t dead but only slightly diminished. And by following our recommended best practices, you can slow its decline.
Although battery life differs from lifespan, the steps you take to extend battery life of your phone, tablet, or laptop mean you will use up charge cycles at a slower rate. That is, it helps to structure your daily use so that you aren’t burning through charge cycles faster than need be.
Summing It All Up
In closing, we present four quick tips to extend battery life and, thus by extension, battery lifespan of phones and tablets:
1. Connect to Wi-Fi when able. Wi-Fi uses less power than a cellular connection.
2. Auto-brightness is your friend. Powering the display is a huge drain on your battery, so keep your display dimmer for longer battery life. And let the auto-brightness setting do its thing to dim your display when able.
3. Beware background apps. Monitor which apps are using the most battery resources when they are not in use and quit or delete the most egregious offenders unless they are a pivotal part of your daily life.
4. Location, location, location. They are the three most important words in real estate and are important to a phone or tablet’s battery life, too. Apps that are constantly tracking your location are constantly using the battery. Turn off location services for such apps until needed.
As for laptops, you can extend battery life by setting the display to dim when on battery power and turn off after sitting idle for a short time. You can also set your laptop to enter sleep mode after a sitting idle on battery power for a set amount of time. Turning off Wi-Fi and Bluetooth when not needed also conserves battery resources. Lastly, Windows offers different power plans; choose the Balanced or Power Saver plan and use the Power plan only when engaged in heavy lifting such as media editing or gaming.