True or false? Battery myths that need to die

Battery technology may not have changed much in the last couple decades, but common knowledge is even worse.

Taylor Martin CNET Contributor
Taylor Martin has covered technology online for over six years. He has reviewed smartphones for Pocketnow and Android Authority and loves building stuff on his YouTube channel, MOD. He has a dangerous obsession with coffee and is afraid of free time.
Taylor Martin
3 min read
Taylor Martin/CNET

Battery technology may not have changed much in the last couple decades, but common knowledge is even worse.

Many people believe the limitations of nickel-based batteries that were prevalent in the early '90s still apply to the more modern lithium ion and lithium polymer technologies we use today.

Here are some common battery myths.

Myth: Leaving your devices plugged will "overcharge" them

False. This simply isn't true -- not anymore, at least. Most smartphone, laptop, accessory and AA or AAA chargers are smart enough to momentarily stop charging once the device is fully charged. It does this long enough for the device to drain two or three percent, then it will climb back up to 100 percent.

Leaving it plugged in like this every single night can have an impact on the lifespan of the battery, but the act of leaving it plugged in isn't as damaging as some people make it out to be.

Computer manufacturers often recommend you "exercise" your battery about every other month by letting it drain fully, then charging it back up. But that's about it.

Myth: You should always let the battery drain completely

Taylor Martin/CNET

False. Today, most batteries never truly fully discharge.

What you see as 0 percent or "dead" when your phone or laptop won't power on is the battery still sitting at somewhere around a 10 percent charge. This is why, when you hold the power button, the screen will turn on long enough to tell you to charge the battery.

So what if you do follow this wrongheaded advice anyway? If you allow your battery-powered devices to go to "dead" each and every day, it will reduce the battery's effectiveness over time.

In other words, top off more often to prolong the battery life of your electronics, and stop letting your phone or laptop die every day.

Myth: Always fully charge a device before its first use

False. To be fair, it doesn't hurt anything to fully charge a device's battery before using it. It doesn't hurt anything if you skip this step, either.

So why do manufacturers sometimes tell you to do it? Fully charging the battery before using a device is to kick-start what's known as a "calibration process," helping the device learn how that individual battery behaves. This is where I tell you that most batteries are self-calibrating, so it's still an unnecessary step.

Myth: Store batteries in the refrigerator

False. Storing a battery in the refrigerator or freezer is not only bad, but can be dangerous. Extreme temperatures - hot or cold and especially for long periods of time - are not good for any type of battery.

Remember, a battery is a collection of chemicals that store energy. Doing something that upsets those chemicals can have dangerous consequences.

To maximize shelf life, Energizer suggests storing "batteries at normal room temperatures (68 degrees F to 78 degrees F or 20 degrees C to 25 degrees C) with moderate humidity levels (35 to 65 percent RH)." This should provide a shelf life of five to 10 years for your standard, cylindrical alkaline cells and 10 to 15 years for cylindrical lithium batteries.

By the way, if you're wondering why your smartphone battery isn't performing as well after just a year or two, that's because the more you use a battery, the less efficient it becomes.