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Everything has a battery now: our phones, computers, game consoles, and even our cars. Only charging to 80% helps our batteries last longer, but most devices don’t give us the option. Here’s why I wish they did.
1Charging to 80% Preserves a Battery’s Lifespan
Most rechargeable devices use a lithium-ion battery. This battery chemistry does not like to be fully discharged, meaning it’s not good to let your battery hit 0% for reasons beyond the device cutting off on you. Do it often enough, and you harm the battery.
Less obviously, charging to 100% isn’t ideal either. While charging to 100% doesn’t inherently cause any problems, leaving the battery at a high state of charge puts unnecessary stress on the battery and shortens its lifespan.
Batteries like to be in a Goldilocks zone of between 20-80%, not too low and not too high. Unfortunately, it’s unrealistic to expect us to babysit our devices to preserve their batteries. That’s what software is for.
Fortunately,some Windows laptops come with the ability to set a charging threshold. Sometimes this option is available in desktop software, and other times you need to dive into the BIOS. MacBooks havea feature called Optimized Battery Charging that also sets charging thresholds.
2Charging Overnight Isn’t Doing Us Any Favors
A habit that many of us have, charging our devices overnight, is causing harm to our gadgets. We plug in our devices when we go to bed, and after an hour or two of charging, they spend the rest of the night sitting at 100%, sometimes cycling through micro-charge cycles to make sure they don’t dip down to 99% while plugged in.
Some smartphones offer software to better manage how they charge. Samsung phones come with a feature called Battery Protection (formerly Protect Battery). This limits a battery’s maximum state of charge. Leaving this set to “Basic” tells your phone that once it hits 100%, stop charging until the phone drops back down to 95%. “Maximum” protection limits your charge to 80%. There’s also an adaptive option that offers to learn your charging patterns so that your device starts charging shortly before you wake up rather than as soon as you plug the phone in.
iPhones use Optimized Battery Charging to perform this task, using the same name for the feature as found on MacBooks.
3You Don’t Want a Docked Device at 100%
Battery protection helps with charging overnight, but that’s not the only situation where we regularly leave our devices sitting at 100%. Some of us connect our laptops to a docking station, which connects them to an external monitor, keyboard, mouse, and other accessories. A smaller number of us use our smartphones instead, making use of Android-based desktops like Samsung DeX. Motorola and Huawei also offer desktop modes, and Google has long experimented with making this a built-in part of Android.
Whether using a laptop or a phone, both tend to draw power from the dock they’re connected to. This means after the first few hours of work, your device is likely sitting at 100% for the remainder of your work day. Not only that, your device is engaged in a trifecta of behaviors that can shorten its life.
For starters, heat puts strain on a battery, and your laptop or phone may get extra toasty when connected to an external display, especially if you’re performing demanding tasks at the same time. Issues with heat dissipation is why Samsung has not included DeX as part of the Z Flip series, which is a smaller device that has less room for air to flow.
Charging also generates heat, since you’re pumping in electricity. So you are making your battery hot due both to a demanding work load and continuous charging.
On top of this, you’re also keeping your battery at a high state of charge. Limiting the charge doesn’t address the heat, but it keeps the battery in a healthier range to handle the tasks at hand.
4Our Earbud Batteries Could Last Much Longer
Many of us have swapped out wired earbuds for their Bluetooth counterparts, especially since companies are increasingly shipping devices without headphone jacks. These earbuds let us say goodbye to tangled cords, but despite costing more money, they don’t last as long. This shorter lifespan has to do with their dependence on batteries (and tiny ones at that).
Not only are Bluetooth earbud batteries miniscule, but they often sit around at 100% for days at a time. That’s because they draw power whenever we return them to their charging cases. This is offered as a feature because it means we can go longer between charging our buds than we could if the buds didn’t recharge inside their cases. Unfortunately, this makes earbuds some of the harder devices to manage a charge on.
5Electric Cars Show Use How This Could Be Done
Vehicles with internal combustion engines easily last decades as long as they aren’t involved in a crash. One of the biggest concerns people have when getting an electric car is whether the battery will last. Few of us want to replace our cars as often as we replace our phones and laptops.
For this reason, virtually every EV comes with an option to limit the charge of the car’s battery to 80%. It’s from buying an EV that I learned about the importance of setting a charging threshold for lithium-ion batteries in the first place.
Remember the issue withChevy Boltscatching fire? If you read past the headlines, you see that the few vehicles this happened to were often at a very high or low state of charge. While this was an issue that General Motors needed to fix (and they did), their advice in the meantime was to avoid charging the car all the way up or draining it all the way down. This wasn’t because of any aspect of the car aside from its battery, which consists of many lithium-ion packs. Cars draw far more power from their batteries than our mobile devices do, but the physics behind their battery chemistry remains largely the same.
The ability to limit a charge is one of the reasons I wanted a Samsung phone over my previous Motorola. To me, it’s a value-add I’m willing to pay for.
I wish charging thresholds were more common across the board, even if it requires digging around in BIOS or system settings. Though, to best look out for consumers, I’d like to see this feature not only available, but enabled out of the box.
