Mobile Battery Life: Fact and Fiction

As the owner of a shiny smartphone, battery life is probably pretty close to the top of your priority list. After all, you don’t want your mobile to die when you’re in the middle of an important call (or a game of Candy Crush). Battery life has been a concern for mobiles ever since the first, battery-draining touchscreens came out, but the good news is that batteries are getting better. In the meantime though, you’re going to need to keep an eye on those juice levels. And to help you out, we’re busting some battery myths, as well as confirming a few facts.

Always Let Your Battery Drain Completely Before Recharging

Sorry guys, this one’s a myth. The story goes that you should let your phone drain to 0% before plugging in as often as possible, but it’s just not true. In the past this wasn’t a myth. Old NiCd or NiMH batteries had what was called a “memory effect,” which meant that if you wanted to keep the full battery capacity you needed to completely discharge them before recharging. However, new Li-ion batteries just don’t have this problem.

In fact, the opposite is kind of true. You should try NOT to drain your battery too often. Ideally, you should be plugging your phone in somewhere around 50% charge to recharge, and only let it go below 20% when absolutely necessary. This so-called “shallow charging” is actually better for modern batteries.

In addition to this, it’s also perfectly fine to leave your phone attached to the charger once it’s full. Leaving your mobile plugged in over night (what some people call “overcharging”) is not a problem.

The Ideal Charge for Storage

Here’s another myth, though the story comes from two sides: if you’re going to be storing your phone for a while then you should either leave the battery at 0% or at 100% (depending on who you talk to). So which is it? In truth, neither of these is a good idea.

Leaving your battery at 0% is not a good plan, and any time you get to 0% you should be panicking to try and find a socket to get more juice. Why? Because a modern battery left empty for too long could lose its ability to hold a charge altogether, meaning you won’t be able to charge it up again.

The opposite side of the story is equally untrue. You shouldn’t store your battery at 100% either, since this could lead to the battery losing capacity (meaning it will hold less charge) which will end up shortening its life span.

So what’s the deal then? In an ideal world you won’t leave your phone (or spare batteries) in storage for more than a few days. Powering them up, using them and charging them is the way to go. If, for some reason, you really do need to leave that phone on the shelf for a while, a 50% charge is the way to go. And that goes for extra batteries and power packs that you may have as well.

Stay Away from Hot and Cold!

Now here’s advice that you should listen to. Both heat and cold are damaging to smartphone batteries, so you do need to be a bit careful. Obviously, you shouldn’t be putting that phone (or battery) into the microwave or freezer. But you should also be conscious of less obvious things. Leaving your phone in the car on a hot day, for example, or leaving your mobile outside too long when it’s below freezing.

It’s unlikely that much damage will happen to the battery if exposed to heat or cold for short periods of time, but in the long run you’re going to end up with shorter battery life. Best to keep things room temperature whenever possible.

Avoid Off-Brand Chargers

Hm, this one’s a bit of a grey area. The story says that you should only ever use the cable that came with your phone or a replacement from the same manufacturer. And this isn’t incredibly true. Chances are that you’ll get a faster charge from your own brand cable, but that doesn’t rule out other cables altogether. A decent cable from a reputable company should be just fine, though you should probably avoid cheap cables. The only real exception to this is USB-C cables, since there are a fair few knock off products around that will give very slow charges. Again though, as long as the cable is coming from a reputable source, you’ll be fine.

Batteries Can Explode!

Again, another difficult one. In general, no, mobile batteries just don’t explode if manufactured properly and treated correctly. Buy a decent phone from a good manufacturer and charge it properly, avoiding heat and cold, and your mobile just isn’t going to explode. Really. Having said that, slip ups do happen (as in the case of the Samsung Note 7). Exploding batteries are nearly always due to manufacturer error or you doing something silly with your mobile that you know you shouldn’t be doing. If that phone does start to feel extremely hot, or if the battery or casing is deformed in such a way that it looks swollen, then treat it with caution. Otherwise, don’t worry.

Batteries Get Worse Over Time

Unfortunately, this one is true, and the process is known as entropy. Just like any other kind of batteries, the Li-ion batteries in your smart phone degrade over time, meaning that they’ll hold less of a charge. You can expect your mobile battery to hold around 80% of its original charge capacity after around a year or so of use.

In short, your battery will last for less time the longer you own your phone (although maybe not if it gets slowed down). And there’s really nothing you can do about this. Some manufacturers will replace batteries, though you’ll need to pay if you’re out of warranty, and some phones still have removable batteries which can also be replaced. If you’re going for replacement, do make sure that you’re using a battery which comes from your phone’s manufacturer to ensure that it’s safe!