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5 Things That Will (and 5 Things That Won’t) Save Your Phone Battery

Photo: Chesnot/Getty Images

Tech Boot Camp is a weeklong series dedicated to getting your gadgets — and your life — into fighting shape with tech tips, software tricks, life hacks, productivity strategies, and gadget recommendations.

The best phone in the world is just an expensive but environmentally unsound thing to skip across a lake if the battery is dead. Here are five things that will — and five things that won’t — save your battery life, both for a long night out and over the course of your phone’s life.

What Will Help

Don’t use “Push” for email on your phone

Imagine if you got up from your couch every 15 seconds to check to see if anyone had left any mail in your mailbox, or perhaps a hanger for cheap Chinese food. It would be exhausting. The same applies to your phone — if you use “Push” email, your phone will ping your email servers constantly, checking to see if you have new messages. Instead, set your phone to retrieve your email every 30 minutes, or every hour if you really want to be relaxed about it. If you open your mail app, it’ll still automatically check for new messages, and if it’s anything vital, someone will probably Slack you anyway.

Low-battery mode doesn’t just have to be for when you have a low battery

If you know you’re going to be out for a while and don’t have a way to charge up your phone, there’s nothing stopping you from turning on low-battery mode even if you’re at 75 percent battery. Depending on how much you use your phone, how old your battery is, and your model of phone, it can triple the amount of time your phone will keep going. For iOS users, you can set a low-battery toggle button by going to Settings > Control Center > Select Customize Controls. On most versions of Android, it should already be on your pull-down menu. The small drop in performance will be more than worth it if it’s 3 a.m. and you really, really need to get a ride share home.

Keep your auto-lock time short

If you check your phone just to see if anyone texted or what time it is, but have your auto-lock set to two minutes, your phone screen may keep on running the display for two minutes. I look at my phone about 60 times per day, and a lot of those times it’s quick glances, so that can add up. Set your auto-lock time to 30 seconds — it’s long enough that you won’t feel rushed if you take your thumb off the screen, but short enough to significantly extend your battery life.

Stay on Wi-Fi when possible

Depending on your cell phone plan, cell data can be expensive. It’s also more taxing on your battery life. When you can, stay on a Wi-Fi network, whether that’s at work, at home, or stuck waiting for an A train that’s been delayed for 25 minutes.

Try not to let your phone’s battery get beneath 50 percent

Long-term, all batteries will lose their ability to hold a charge. That said, you can stave off that decline by not allowing your battery to dip below 50 percent charge whenever possible. The reasons why you should charge your phone when it hits 50 percent are wonky — anodes, cathodes, and solid electrolyte interfaces are all involved. To keep it very simple: there’s a concept called “depth of discharge” — how much of the total battery is used before it gets recharged — and you want to keep your depth of discharge as shallow as possible. On an average phone battery, if you regularly use 100 percent of your battery’s power, your battey will lose its ability to hold a charge after 300 to 500 cycles. Top off your phone at 50 percent, and you get 1,200 to 1,500 cycles before your battery starts to hold less charge. Essentially, when you get to work or back home, plug your phone in.

What Won’t Help

Closing out all your apps

Feel free to swipe away all your open apps if you want to Kondo up your phone, but it won’t make much of a difference on your battery life. Unlike a PC or web browser chugging away with multiple applications or tabs running, open apps on your phone are more like a screenshot of what you were doing in the app when you were last using it, and drain no power from your phone whether it’s open or closed. (The one exception is an app running in the background that’s also using location services.)

Letting your battery drain to zero percent

This is a tricky one, because this advice was actually true for older nickel cadmium or nickel-metal hydride batteries, which would “forget” what their full capacity was. Draining them to zero allowed them to reset, and hold a full charge. But lithium ion batteries — and every phone you can buy or have bought in the past ten years uses a lithium ion battery — don’t have this quirk, and don’t need to be drained to zero. In fact, doing so slightly shortens your battery’s life (see above).

Turning off Bluetooth and Wi-Fi

It makes gut sense — shutting down your Wi-Fi and Bluetooth should eke out a few extra minutes of life on a dying battery, right? Eh, not really. Wi-Fi actually uses less battery life than cell data, and while actively using Bluetooth can drain power, just having it on in the background uses almost no power. However, if you’re in an area with patchy reception — where you’re constantly going on and off your cellular data network, go into airplane mode. Your phone constantly struggling to find a connection will kill your battery life quickly.

Having a dark background or reading white text on black (if you have an LCD screen)

This is a tricky one, because it’s true that phones with higher-end OLED screens will see power savings if they use black as much as possible, because each individual pixel lights up on an OLED screen, and darker pixels drain less power. But an LCD screen doesn’t do that — it just uses a backlight for everything. So on an all-black phone with just white text on an LCD phone (i.e., every iPhone except for the iPhone X, iPhone XS, and iPhone XS Max) running dark doesn’t get you any extra battery time.

Not charging your phone overnight to avoid “overcharging” it

Another persistent myth: there’s the idea that if you charge your phone overnight, you’ll erode its lifetime by giving it too much juice. All modern phones are smart enough to know when they’ve hit 100 percent charge and stop taking on current. That said, your phone will generate heat while charging, and lithium ion batteries generally don’t like heat. So charge your phone on your bed stand, not underneath your pillow. (Or, better yet, charge your phone overnight in another room to stop yourself from going on late-night Twitter jags. Unless you found this article via a late-night Twitter jag, in which case: keep on doing what you’re doing, and click a few more articles while you’re here.)

5 Things That Will (and Won’t) Save Your Phone Battery