Photograph of a phone charging next to a laptop

Ultimate Guide to Charging your Phone

We use our phones for practically everything, and so much usage leaves our batteries drained - but there are many ways to prolong your battery life, and a lot comes down to the way you charge it. Here’s everything you need to know about charging your smartphone.

What is a phone battery?

A phone battery is a small container stored inside the internal hardware of your device. A battery is, essentially, a sort of chemical energy that is reignited each time you place your phone on charge. The electricity powers the separate parts of the battery (the current, anode, and cathode) and is transferred from one end to the other to recharge your phone. 

Ultimately, a battery’s job is to keep your phone on and alive. If the battery fails, your entire smartphone will be unusable, so they’re a major component for any electrical device. 

Type of phone batteries

There are two types of batteries you could have in your smartphone. 


A removable battery can be physically removed from the back of your phone and replaced by another if it dies or isn’t functioning properly. You can usually do this yourself by simply sliding open the back panel and lifting the battery out. 

While removable batteries are helpful for quick replacements and resets, a disadvantage is that anyone is able to remove it, so you’re at a higher risk of theft. If your smartphone is lost or stolen, it’s untraceable without the battery. 


On the other side of the coin, there are non-removable batteries, which (despite the name) can be taken out, but only by a professional. They are built into the hardware, with no back panel to access them. 

This provides extra security, as only people with the right knowledge can accurately remove the battery. An added bonus is that if your phone is stolen, the battery can’t easily be removed, making it easier to track down the device. 

Smartphone designs also benefit from having a non-removable battery, as they don’t have to accommodate a back panel, so are usually sleeker and thinner. However, if you need to swap your battery out, it’s going to be harder and more costly. 

Types of phone chargers

In terms of charging your battery, you’ll find there are three different types of chargers out there.


This is what you’d probably know as the ‘standard’ way of charging. This form of charging is very simple to understand. It involves connecting your phone via a cable to an electrical power outlet, be that a plug socket or powered USB port (like on a laptop or PC). 

Most modern phones have either a USB-C, Micro USB, or lightning port for connecting a charger. This varies by model and manufacturer.

Despite newer technology coming out, charging with a cable is still the fastest way of recharging your smartphone.  


Wireless charging is becoming increasingly popular in recent years and is remarkably simple to understand. 

All you have to do is place your phone on top of a charging pad, making sure to align the back of the phone (where the battery is) within the magnetic ring, and the automatic connection will start supplying electricity. 

The term ‘wireless’ is slightly misleading, as there is actually a cable linking the charging pad to your mains, but it’s the fact you don’t have to physically plug your phone in. . 

The Qi (“chee”) wireless technology standard is used almost exclusively across the industry, so you don’t have to worry about different manufacturers releasing pads that only work with specific devices. Saying that, Apple Magsafe uses magnets that only snap to iPhone 12s which could signify the start of a new trend. 

Not all devices are compatible with wireless charging, though, so you’ll have to make sure your smartphone has Qi technology before you buy anything


Portable chargers are another way of charging ‘wirelessly’. Sometimes referred to as power banks, power packs, or external batteries, they can charge your phone while you’re out and about, travelling, or away from a charging station. 

To use them, you need to charge them up beforehand, and then use a cable to attach the power pack to your smartphone. The juice inside the portable charger will then transfer to your phone’s battery. How much charge you get out of one entirely depends on how much capacity the portable charger has. 

These types of chargers are perfect for people on the go, travelling or camping

Fast charging

Fast Charging is a souped-up version of charging that (non-surprisingly) charges your phone faster. You need a battery that is designed to take high levels of voltage, as well as a charger that supports fast charging. The majority of modern smartphones, like the Samsung Galaxy S20 Ultra and iPhones 8 to 12, support this type of charging.

Fast Charging is convenient for when you need your phone back quickly, such as at pit-stops while travelling, or ahead of an important meeting. While doing this every now and again is perfectly fine, fast charging causes your battery to heat up a lot, which can cause long-term damage like reduced battery life. 

We recommend only using fast charging when necessary, and as infrequently as possible, in order to preserve the lifespan of your phone’s battery. 

When should you charge your phone?

You should charge your phone little and often, rather than in huge bulks from 1% to 100% as it’s about to die. This method is ineffective because modern lithium-ion batteries don’t need to be fully charged, and doing so places extra stress on the battery, causing it to deteriorate quicker. 

Try to stay off your phone while it’s charging to avoid any extra competition between the charger and your smartphone’s battery, as this will put more strain on it and cause it to charge slower.

Also, you should avoid leaving your phone on charge overnight because the constant electricity can wear out your battery and cause it to overheat. If you’re asleep, you can’t turn the charger off once you reach 100% (or, more optimally, 80%), so it’s best to leave it off charge. 

However, if your phone is about to die and you have no choice but to put it on charge before going to sleep, remove the case and make sure nothing is covering the phone. 

How temperature affects your battery

Extreme temperature changes can damage your battery. Phones are extremely susceptible to heat. They get hot with daily usage anyway, such as a long phone call, so adding any more heat on top of that is a big risk. Phones don’t have high-speed fans like laptops, so can’t cool themselves down quite so effectively. 

Causes of overheating

  • Your battery is usually the first port of call to check on if your phone feels hot. As we’ve said, batteries can become very warm, especially if they’re on charge. The fateful 2016 incident surrounding Samsung Galaxy Note 7 phones exploding was due to faulty, overheating batteries
  • Non-stop usage can also cause overheating, such as playing games, watching films, or having multiple apps open simultaneously. This can slow down your processor, as well as eat up your battery life
  • Leaving it exposed to the elements is an obvious risk, as sunlight can warm up the outside and inside of your smartphone exponentially. When outside, keep your phone out of direct sunlight by placing it in a shaded area or inside a bag or pocket
  • Keep your phone out of cars, especially in hot weather, as they become saunas and can melt the inside components of your phone
  • Remove the case in extremely hot weather to eliminate any extra layer adding or retaining heat

Just as hot temperatures can damage your phone, so can cold. In those blustery winter months, make sure to regulate your phone’s temperature by storing it inside pockets when out and about, and never leaving it in a car. 

If you have no other option, simply turning your phone off can allow it to withstand a greater temperature range, as nothing is running in the background. 

How to make your battery last longer

There are multiple ways of making your battery last longer. A big way to help preserve your battery’s lifespan is to keep it between 40% and 80%. This way, you don’t apply any extra stress or heat on to your battery, which keeps it functioning at a higher capacity for longer. 

Other methods include closing background apps that aren’t in use to prevent your smartphone from expelling any energy on them, turning off notifications when they’re not wanted or needed, lowering your screen brightness, switching to airplane mode, and more.

Phones with the best battery life

You can get ahead of the battery game from the very beginning by purchasing a smartphone with a good battery life

Battery life is measured in milliamp hour (mAh). The higher the mAh, the longer the battery will last before needing to be recharged. 

With technology today where it is today, you’ll generally find smartphone batteries in the region of 4,000 to 5,000mAh, though some brands have surpassed this. 

If you really want power, the Oukitel K13 Pro has an 11,000mAh battery, and the unmatchable Energizer Power Max P18K boasts a whopping 18,000mAh battery. Of course, there are other things to consider when looking at smartphones, but this shows you how far batteries can be pushed. 

Top tips for charging your phone

You might think charging is as simple as plugging in your phone, but there are many things you could do to charge better and to keep your battery healthy. Here are our top tips:

  • Keep your battery between 40% and 80% when possible
  • Don’t charge overnight or to 100% 
  • Use Fast Charging infrequently to preserve battery health
  • Keep your phone away out of the sun and the cold
  • Use battery saver mode whenever possible
  • Use airplane mode when necessary
  • Don’t use your phone while charging
  • Don’t use your phone all day, everyday

We hope this guide has been helpful. Why not use your newly-learned tricks on a new phone from Asda Mobile?

Go Pay As You Go

The easy way to get more from your mobile

Mobile phone illustration

Say hello to handsets

No commitment, no limits
No commitment, no limits

With no commitment you have the freedom to flex your usage whenever you need to.

Powered by Vodafone
Powered by Vodafone

Powered by Vodafone with up to 99% UK population coverage.

Cap your spend
Cap your spend

Put a limit on how much you spend every month so you don't need to worry about getting a big bill.

Always easy to get through and speak to real people. Problems easily sorted & resolved with good cheap realistic prices. Very happy with Asda Mobile!


Very good network cover especially in remote countryside and best date deals and flexibility to change monthly plans.


I get what I pay for and it all works fine. Now the billing issues from the switch to Vodafone network have been sorted, job's a good 'un.


Great price for what I need. Always had great customer service when I've rang up.


Asda Stores Limited (registered address: Great Wilson Street, Leeds, LS11 5AD) trading as Asda Money, acts as a credit broker not a lender, and is authorised and regulated by the Financial Conduct Authority. Asda Stores Limited only offers finance from a restricted range of finance providers. Finance provided by PayPal Credit. Terms and conditions apply. Credit subject to status, UK residents only. ASDA Stores Limited acts as a broker and offers finance from a restricted range of finance providers. PayPal Credit is a trading name of PayPal (Europe) S.à r.l. et Cie, S.C.A. 22-24 Boulevard Royal L-2449 Luxembourg.