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How to charge a battery: 5 myths debunked and 5 proven tips

There's some much bad advice out there about the best way to charge your smartphone and laptop batteries. We set the record straight.
Written by Adrian Kingsley-Hughes, Senior Contributing Editor

Rechargeable batteries are in everything these days. While there's a huge convenience to not having to replace batteries (not to mention the environmental benefits), you're either looking at getting it replaced or buying a new device once that battery dies.

Because the life of the rechargeable battery is usually the determining factor when it comes to the longevity of a gadget, doing what you can to keep that battery in tiptop condition is recommended.

But this has led to a load of charging myths out there on the internet, aimed at people wanting to look after their devices as best as possible.

Let's take a look at five of the most common myths:

#1: Let the battery go flat

One of the persistent myths that I come across regularly is that it's good to let the battery in whatever device you're using go totally flat every so often. The idea is that it gets a better charge when you do this, and it somehow "recalibrates" the battery.

This might have been true for older battery technologies; modern lithium-based batteries don't need this at all. In fact, while it's quite safe to do this with high-quality batteries, I've come across lower-quality batteries that this practice has damaged.

#2: Keep devices plugged in and on charge all the time

The idea here is that if a device is plugged into power continuously, there's little to no battery wear.

Not true. Not only will some devices still be using the battery, even if they are not, having the device plugged in all the time can cause wear through overheating.

#3: Only use a genuine charger and cable

While poor-quality chargers and cables can cause problems -- such as damaging devices, causing electrical shocks, and even starting fires -- there are plenty of good-quality third-party accessories out there from companies such as Anker, Amazon, Zendure. Not only are these devices as good as genuine chargers and accessories, but they are also a lot cheaper than accessories you buy from the likes of Apple and Samsung.

#4: Never charge to 100%

This myth has been around for years and has gained more traction recently with Apple's introduction of an optimized battery charging system that keeps the battery at 80% charge for as long as possible, only adding the final 20% just in time for the user to start their day.

While it's not good to keep a battery charging for a lot longer than needed, there's no problem with charging a device to 100%. Batteries have been designed to work like this and have built-in charge regulators that mean that it's safe to take batteries to 100%.

#5: Never use wireless charging

While I'm not a fan of wireless charging -- it's slower and more inefficient and can cause a device to heat up more than normal if it's inside a case -- under normal conditions, there's nothing wrong with using it.

Like all other forms of charging, the wireless charging mechanisms carefully control the power being delivered to the battery to ensure a safe charge.

If you regularly use wireless charging with a smartphone, then I recommend making sure that any case you use is wireless charging compatible and that you use a quality charger.

Tips for keeping your battery in tiptop condition

OK, with the myths out of the way, here are my top tips for getting the most from the batteries in your rechargeable devices:

  • Keep battery away from extremes of hot and cold
  • Do not drop or damage a battery or a device containing a battery
  • Use good quality chargers and accessories
  • If you are going to store a device for an extended period of time, then it's recommended you charge the battery to 50%
  • Once the battery is worn, get it replaced with a high-quality replacement by a reputable repairer (or do it yourself)
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