Mistakes Everyone Makes With Lithium Batteries (And How To Avoid Them)

Lithium-ion batteries revolutionized the world when Sony brought them to the mass market in 1991. Compared to previous rechargeable battery technology, they were lighter, more energy-dense, last longer, and continually cheaper to make — essentially, better in every way. But even though they've become a cornerstone of the consumer electronics and EV markets, they're not perfect. 

The industry is rapidly moving toward revolutionary new battery technologies due to the issues and limitations lithium-ion presents. Despite the tech's ubiquity over the past decades, many people don't know about these issues and make mistakes with lithium-ion-powered devices — sometimes with grave consequences.

Flawed though lithium-ion (abbreviated to li-ion) may be, knowing about these flaws can make your batteries last longer and reduce risk. In most cases, small changes to your habits, like how and when you charge your batteries, is all it takes. We'll be focusing primarily on batteries in consumer electronics, like phones, but everything here applies to lithium-ion batteries generally. Here are 12 mistakes you might be making with your li-ion batteries, and how you can avoid them.

Lithium ion batteries is hate being fully charged and hate being fully discharged. Too-high voltage and disequilibrium in the battery's chemistry cause gradual, permanent wear to a battery, reducing charge capacity. All lithium-ion batteries lose capacity with use, but overcharging and under-charging exacerbates that process. Therefore, follow the 20-80% rule.

If you want your lithium-ion battery to last as long as possible, keep the battery in the Goldilocks zone, between 80% and 20%. Modern phones like the iPhone 15 and above let you stop your phone from charging when it hits 80%, and you can automate your daily activities with an iPhone to get a notification when it hits 20%. One of my favorite Mac apps to improve your Apple experience is a charge limiter called Al Dente. Similar options exist for Android and Windows. Obviously, this is harder if your device doesn't let you easily monitor the battery level, such as a pair of Bluetooth earbuds or a cordless drill from the best brands.

Now, this comes with one clear tradeoff: you're forfeiting almost half of your battery. Most phones these days are lucky to get a full day's battery on a single charge. Frequent charging is tedious and sometimes unfeasible, and battery replacements are getting easier and cheaper. When we polled people about how often they upgrade their phone, over half said they do so every two to three years, which is about when the battery would need to be replaced, anyway. If that sounds like you, maybe it's not worth the work.

Just as Goldilocks doesn't like too-hot porridge, lithium-ion batteries don't like getting hot either. A battery only needs to hit 85 degrees Celsius before degradation begins. For reference, most CPUs can safely run at a maximum of 90 degrees Celsius, and the CPU is quite close to the battery in portable electronics, particularly smartphones. Even EVs need cooling systems for their batteries. It's an unfortunate reality: Batteries shouldn't get too hot, but they often power devices that produce a lot of heat.

Many devices, like iPhones, will become partially disabled or shut off completely if they get too hot, to avoid damage to their components, batteries included. EVs keep catching on fire due to thermal runaway (where batteries will spontaneously combust at rest), which is another reason why the industry is so eager for a game-changing breakthrough in EV batteries. It's likely this is the same reason vapes are randomly exploding in people's pockets, too.

All of this is to say that you should keep your batteries as cool as is reasonably possible. Avoid using a li-ion powered device out in direct sunlight for too long, or leaving it in a hot car. Charging heats up a battery too, so avoid charging while gaming or with your phone under a pillow. Maybe reconsider taking your laptop with you to a hot beach for the same reason.

Continuing the Goldilocks metaphor, batteries don't like being too cold either. Most devices have a safe operating temperature threshold, but batteries especially suffer from cold weather. The reason, again, has to do with chemistry. Cold causes batteries to produce less energy and lose capacity. If you've ever noticed that your phone runs out of battery faster in the winter than in the summer, this is why.

Extreme cold can cause permanent damage; li-ion cells can expand and crack. So yeah, never leave your Milwaukee batteries in the cold, and expect reduced range in an EV when it's winter in Montana. So what's the solution? There's not much good news for EVs, but keeping batteries warm works for the rest. Consider putting your electronics in your pocket, close to body heat, when outside on a cold day. Avoid leaving them in, say, a parked car outside.

Ironically, the heat generated from charging may be a good thing in the cold. Using MagSafe battery packs for iPhone could keep your battery warm when you're out and about. Avoid using battery-powered devices as much as is feasibly possible in extreme cold, unless they're designed for it. Extreme cold might make the Apple Watch Ultra 2 worth it if you need something tough enough to climb Mount Everest.

Please, for the love of all that is holy, never discard lithium-ion batteries in your normal trash or recycling bins. First, according to the Environmental Protection Agency, they can catch fire on the way to their dumping destination. Second, when dumped, they break down and release toxins that pollute the environment. Electronic device that have lithium-ion batteries require their own special recycling, too.

Old batteries aren't worthless, since 95% of them can be recycled. Recycling them couldn't be easier, too. There are free recycling locations at major businesses, such as Best Buy and Home Depot, in addition to your local municipal facilities.

Of course, you could always sell an old li-ion-powered device to make a bit of cash. Someone else may be willing to spend the time and money to replace its battery. Double-check to make sure it doesn't have any trade-in value with its manufacturer or a third party, as well. Apple, for example, will give you trade-in value for old devices you can apply to a new one. Even the iPhone 8 (released in 2017) can net you $40 of value. We're in the midst of a massive e-waste crisis, so recycling things to let that material go toward sustainable tech products made from recycled material is a no-brainer.

Throughout the 2010s, you probably remember it becoming increasingly common knowledge that leaving your phone plugged in to charge overnight was bad. Luckily, this is one of the more common smartphone myths you can stop believing. Phone charging has improved a lot since then. Modern devices don't trickle-charge (charging repeatedly any time they drop below 100%) like they used to. Plus, most phones charge at their fast speed for the first 80% and then intelligently slow down, only reaching 100% when you wake up. In short, don't stress about leaving your phone plugged in overnight. It's far less problematic than it used to be.

That said, there are things you can do to further reduce the risk to your battery. Many modern phones (like the Google Pixel) also support bypass charging, where they take power directly from the plug rather than from the battery to reduce wear. And again, many phones (the iPhone, as mentioned) support charge limiting. Barring all that, you can always put your phone in airplane mode and low power mode while asleep and charge it the next day; you probably don't want those notifications interrupting your sleep, and your phone likely supports fast charging to quickly get it back up full before you leave home.

We've mentioned already how li-ion batteries prefer to stay above a 20% charge level. As perhaps further evidence of how averse they are to low charge, they will stop charging altogether if fully drained; either the battery won't work, or will hold such a small charge it's useless. To be clear, we're not talking about a phone dying at 0%, or a device that's been worn out from several years of regular use. We're talking about a battery that hasn't been charged in a long time. Say, for example, you leave an old Kindle in the closet, and when you pull it back out, charging doesn't revive it. You may be able to give batteries like this the Lazarus treatment.

The key is a basic USB charger, according to Adrian Kingsley-Hughes from ZDNet, particularly one that's not very powerful. That old charging brick in your junk drawer belonging to some device from years ago is perfect. All you have to do is leave the battery charging, ideally with some sort of voltage meter to track how much it's drawing. Lots of major power bank brands these days will tell you how much power a connected device is drawing.

Kingsley-Hughes recommends putting the batteries in a fireproof container as extra precaution and monitoring heat levels with a thermal camera, and leaving them to charge for at least 20 minutes. Once it starts to take a charge again, give it a few more hours. If all goes well, the battery will be revived and capable of recharging like before.

If you've been following the news at all, you know that electric vehicle fires are every firefighter's nightmare. They burn ferociously for hours and are difficult to extinguish completely since they can flare up a second time. As just one example, it took 50,000 gallons of water and a plane to put out a burning Tesla Semi truck. Li-ion batteries are to blame, and similar (although much smaller-scale) conflagrations can happen with any electronic device that has them, like e-bikes. These fires typically occur when a battery is overcharged, overheated, damaged, or defective. If one of your li-ion devices bursts into flames (or worse, your EV), then don't treat it like a typical fire.

Even before you see flames, take note of any strong smells, a swelling battery casing, leaking fluids, or extreme heat. If you see any of the previous (or a battery has already caught on fire), then unplug it and take it outside, if possible. You can try to extinguish it yourself if you have a hose or a bucket, although it would be ideal to use a fire extinguisher. Throughout this process, avoid inhaling any of the smoke coming off the batteries, as it's highly toxic. If it's an EV that's on fire, then the only thing you should do is evacuate the area, call emergency services, and make sure everyone's okay.

Following off the previous point, swelling is among the most alarming indicators of a battery's fire risk. A swollen battery in your laptop or phone will look almost like a pillow and may push other components out of the way as it expands. It's common for devices with swollen batteries to bulge and have gaps in the case. You should not use a device with a swollen battery, nor should you charge it. The battery needs to be removed ASAP, ideally by an expert. Don't leave it inside a building, and keep other people away from it. iFixit recommends taking pictures of the swollen battery, turning the device off, putting it in a fireproof container, and then bringing it to a professional for removal. 

If you try to remove it yourself, discharge the battery (leave it on until it runs out of juice), then put on goggles, gloves, and a mask, and take it outside. Try to manipulate the battery with something other than your fingers when possible, like a pair of tongs. iFixit recommends placing the device in a metal bucket of sand where it won't burn anything else if it goes up in flames. Remove the battery according to its own replacement guide if one's available, or with the help of a YouTube guide. If it's a smartphone, you'll probably need some isopropyl alcohol to dissolve the glue underneath. Find an e-waste collection site and take the battery there in a fireproof container. Do NOT ship it by mail or throw it away.

Everyone has probably at least heard of Apple's Batterygate scandal, when the tech giant was caught red-handed throttling older iPhones. It seemed like Exhibit A for planned obsolescence; Apple was unscrupulously nudging owners of older iPhones to upgrade. However, a pervasive myth sprung up after this debacle, creating a fear that updating one's device would make it slower. This isn't true. There are a number of reasons you should keep your phone updated, and the only real reason not would be concerns over stability issues or bugs in the latest major version of an OS. In most cases, updates make your device work better, not worse. Having said that, what about the whole Batterygate scandal? What's the solution if an update has slowed down your device? Simple: replace the battery.

A device with a worn-down lithium ion battery doesn't just have reduced capacity, it has reduced power output. Reduced power output results in performance degradation since, obviously, it can't supply the power all its components need. In the case of iPhones, Apple was throttling old iPhones' processors to stop them from shutting down at random. A new battery solves that issue and brings back the performance that was lost. This tends to be the case for just about any electronic device. If the battery barely holds a charge, you will likely see performance improvements by replacing it.

One reason lithium-ion batteries are superior to the battery options that came before them is that they don't lose as much charge (technically known as "self-discharge") when left unused for long periods of time. However, the amount of charge they have when put in storage could have a negative effect. Avoid putting away a battery (or device with battery) when it has a low charge, or too much. Permanent damage can occur to a battery that's at a too-low charge level for too long.

Giving a hard number is difficult since manufacturers will often recommend varying levels of charge. For example, DJI (maker of drones and cameras) recommends keeping a battery between 40% and 65% any time a device will sit unused for 10 days or longer — so even if it's not going into storage, leave it at that percentage if you don't plan to use it for a while. The reason for this is the same reason you should only charge your battery up to 80% and keep it from falling below 20%: the chemistry will get out of whack. Also, periodically charge devices that have been in storage for a long time.

Most people understand that lithium-ion batteries have a limited number of charge cycles, between 300 and 500, although modern batteries can get up to 5,000 cycles in certain applications. Once a battery extends beyond its maximum of charge cycles, it will either stop working or hold a severely reduced capacity. Many people misunderstand how cycles work thanks to those numbers, and thus misunderstand the longevity of their devices. If you use and charge a device on a daily basis, then that means a lithium-ion battery should go kaput after just a year, right? Not exactly.

Rather than being based on a single charge, cycles are based on a percentage of a charge. So charging from 20% to 80% isn't a full cycle, it's only 60% of a cycle. Charging from 40% to 80% the next day completes the cycle. With that knowledge in mind, your devices likely last much longer than you initially thought and don't require a battery replacement as soon.

If you only take one bit of wisdom away from this article, let it be this. Never, ever puncture a battery with a sharp object. Without getting too deep in the scientific weeds, stabbing a battery upends the delicate equilibrium of the components inside, creating a short circuit that leads to a (oftentimes explosive) fire. iFixit impaled some batteries in a YouTube video to demonstrate this fact so you don't have the rude awakening for yourself when replacing the one on your phone.

It's not guaranteed that a punctured battery will burst into flames or explode; smaller batteries at a low charge level punctured by a sharp plastic object — rather than metal — will mostly only smoke and spit a few sparks. A bigger battery that's closer to full charge, on the other hand? That's a miniature Armageddon. When iFixit punctured a fully-charged laptop battery in their demonstration video, it erupts like a small volcano. Needless to say, this could injure you and possibly burn your house down. So be extra, extra careful handling any li-ion batteries.