Is it True That Power Banks Damage Your Phone’s Battery?

Key Takeaways
  • Choose reputable brands with proper safety standards to avoid damaging your phone's battery. Low-quality power banks can cause issues.
  • Both use lithium-ion technology, with power banks storing and transferring energy. Capacity is measured in mAh or Wh.
  • Avoid full charge cycles and extreme temperatures, and use certified chargers and power banks. Recommended models include Anker Portable Nano, Anker 737, and SHARGEEK Storm 2.

The debate surrounding the safety of power banks has been swirling around the internet for years. With literally hundreds, if not thousands, of options available, it can be confusing to know which ones are safe. So, how can you choose a safe power bank, and are they inherently risky for your mobile device?

This guide will try and explain how smartphone batteries and power banks work, and then, address the question of whether power banks can damage a smartphone’s battery.

How Smartphone Batteries Work?

On the most basic scale, smartphones contain lithium-ion (Li-ion) batteries that convert chemical energy to electrical energy. Li-ion is one of the most popular types of rechargeable batteries that exist today and is exclusively used in almost all modern-day consumer smartphones. At the very core, they rely on the movement of the lithium ions between two electrodes.

Mobile phones today almost exclusively use Li-ion batteries

↪ Li-ion Batteries’ Working Mechanism

For a brief overview, the way Li-ion batteries work is that they consist of a cathode (which is usually a thin lithium oxide compound), an anode (graphite), an electrolyte (a lithium salt dissolved in a solvent) and a separator (keeps the anode and cathode separate, but allows ions to pass through).

When you connect your phone to a charger i.e. an external power source, the current (electrons) start to flow towards the cathode. Lithium ions then flow internally via the electrolyte from the cathode to anode. As these lithium ions then embed themselves within the anode, its chemical potential rises. The difference in chemical potentials between the cathode and anode create a potential difference which is how the battery is able to store energy.

A schematic diagram showcasing how a Li-ion battery charges and discharges

The complete opposite of this happens when you use your phone. The process reverses and electrons flow from the anode through the external circuit of your device (essentially powering it) towards the cathode. The Li+ ions however move internally again, from the anode to the cathode.

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How Do Power Banks Work?

Power banks consist of an internal battery that is used to store electrical energy, which can then be transferred to any device you wish to charge. Similar to the mechanism described above, power banks also use Lithium-ion cells, and can charge or discharge in a similar way as a phone.

A cutaway view inside a typical power bank

The battery capacity within a power bank also varies, and is measured in mAh or Wh. This means that a higher capacity allows for charging your device more times. Like the name suggests, a power bank is essentially a supply of electrical energy, stored chemically within its own battery.

READ MORE: Reverse Charging – How to Use Your Phone as an Improvised Power Bank ➜

Do Power Banks Damage Phone’s Battery?

Power banks can damage your phone’s battery if they don’t meet safety regulations. This might happen if they’re made by unreliable manufacturers, priced surprisingly low, or are incompatible with modern smartphone charging standards.

When looking for a power bank, try and opt for something that is compatible with the device you’ll be charging, and with these, it’s best to not compromise on quality under any circumstances. A low-quality power bank can not only shorten the lifespan of your phone’s battery but also pose a safety risk due to the lack of safety features like overcharging protection or temperature regulation.

READ MORE: Is Wireless Charging Bad for Your Smartphone Battery ➜

When are Power Banks a Risk to Your Phone’s Battery?

Not all power banks are made the same and are more different than they are similar to one another. Some would be perfectly normal to use on a day-to-day basis, while others could be a ticking bomb, waiting to destroy your battery.

This is why it is important to keep certain elements about these in mind before opting for a suitable power bank for your phone.

1) Insufficient Capacity & Low Voltage Rating

Make sure that any power bank you choose has a battery capacity that is larger than the capacity of your device. It doesn’t have to be a phone per se, but any device you want to charge. Not doing this will result in a scenario where the power bank would drain out before your device is fully charged, even once.

A low-capacity power bank runs out of battery power more quickly.

Moreover, try to look for power banks that match your phone’s voltage ratings. This shouldn’t be an issue with modern-day power banks, but let’s say, for example, your phone battery charges at a minimum of 5V and the power bank used to charge it is <5V, say 4.5V, the phone won’t even charge in most cases, and not only that, but whatever juice you have left in your phone will eventually drain out.

2) Poor Quality Internal Circuitry

With the influx of cheap power banks making far-fetched claims in the market, it’s no surprise that manufacturers may cut corners on quality to reduce costs. More often than not, the internal circuitry is the first to be compromised, even if it means improving aesthetics to boost sales.

Using a power bank with poor quality internal circuitry immediately puts your device at risk. While most modern mobile phones have built-in safety measures to prevent damage, they aren’t completely foolproof.

Inside view of a cheap power bank.

You don’t necessarily need to pry open the power bank to check its quality, but clues like a suspiciously low price compared to the claimed features, aggressive marketing tactics, and a lack of brand reputation can be good indicators of a potentially risky product.

3) Lack of Compliance with Safety Regulations

The most crucial part of a power bank is inarguably how safe it is in real-world scenarios. When buying one, look for certification marks that show the product complies with safety standards and has undergone testing to ensure those standards are met. Look out for standards and directives like UL, RoHS, WEEE, and FCC.

An unsafe power bank can easily damage your device.

4) Poor Quality Charging Cables

In some cases, even with the right power bank, there might be issues with the intermediary: the cable. This charging cable acts as a bridge that supplies electrical current from the power bank to your device. If the cable mismatches your device or, worse yet, doesn’t comply with safety standards, it can just as easily damage or degrade your smartphone’s battery.

An unsafe cable is equally as dangerous as an unreliable power bank.

Make sure that the charging wire you choose is high-quality and follows set standards. Try and go for manufacturers that are reputable and have an established standing in the industry with a reputation for quality and safety.

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How to Charge Your Phone Properly?

It’s important to note that regardless of the power bank you use, certain charging habits can make your battery degrade faster over time. One of the main disadvantages of Li-ion batteries is that they gradually lose capacity over time. This is why, it eventually boils down to the user to slow down this process as much as possible.

1. Avoid Full Charge Cycles

Try and prevent charging in full cycles. Instead charge your phone in intervals from when the battery percentage is 20% up to 80%. This would not only help elongate the battery health, but also with fast charging support in most phones nowadays, charging in full cycles is unnecessary in most cases.

2. Avoid Charging in Extreme Temperatures

Avoid charging your phone in extremely hot or cold temperatures. Keep in mind that the phone’s battery will generate additional heat while charging, even if the outside temperature doesn’t feel too hot. Modern smartphones usually now come with built-in safeguards and will automatically refuse to charge if they detect really high internal temperatures.

Try and avoid charging in extreme conditions.

3. Use Certified Chargers and Power Banks

This couldn’t be stressed enough—use good quality charging hardware. This is because a charger is an important part of shaping your smartphone experience. You might not realize it when using a newer device, but poor charging habits and hardware can damage it sooner than you think.

It’s not strictly necessary, but try to use the manufacturer-recommended hardware for charging all of your devices. For instance, popular companies like Samsung, Apple, and Xiaomi have their own dedicated charging solutions, which are not only safer options but also integrate better into the overall ecosystem.

Apple’s MagSafe Battery Pack

In recent times, charging methods and hardware have become much more sophisticated and smarter. In most cases, the phone itself knows when to stop charging, even when plugged into a charger. Some phones will automatically detect dangerous chargers or power banks and refuse to charge.

Phones also now have the option to smartly charge up to only 80%, and since they learn your charging habits, they gradually charge from 80% to 100%, especially when they expect that you’ll unplug the phone soon.

READ MORE: Myths vs Reality – Can You Use Your Phone While Charging? ➜

Best Power Bank Recommendations

Now that we’ve covered what to consider when buying a power bank, let’s look into some of our recommendations. We’ll see what each option brings to the table to help you choose the best one for your needs, that suits your budget.

1. Best Under $50: Anker Portable Nano

The Anker Portable Nano comes in at almost $30, offering 22.5W of fast charging and a 5,000mAh battery capacity.

Anker Portable Nano ($30)

While it may not be the fastest charger or have the most capacity, it’s very small, lightweight, and easy to carry around. On the plus side, its design allows you to use your phone while simultaneously charging it, and it plugs in directly to your phone via USB-C, so there’s no intermediary to worry about.

2. Best Under $130: Anker 737

The Anker 737 comes in at almost $110, offering 140W of back and forth charging support and a 24,000mAh battery capacity.

Anker 737

This power bank is priced a bit higher for its feature set, but offers great quality and a robust build, which is exactly what you may need for a device coming in at 1.4 pounds. It can charge itself in less than an hour and is plenty to refuel not just your phone, but also any laptop you may have.

It also has a digital display that shows its remaining battery percentage, wattage output from each port, time remaining to charge the device connected and the charge cycles remaining.

3. Best Overall: SHARGEEK Storm 2

The SHARGEEK Storm 2 comes in at almost $200, offering 100W of charging support and a 25,600mAh battery capacity.


The see-through design of this device is what makes it stand out from the rest. Not only that, but it has a decent battery capacity, enough to charge most of your accessories simultaneously, at least once. It also packs an IPS screen, with information such as the battery remaining, input/output wattage, current, voltage, battery temperature and operating time.

READ MORE: 10 Methods For How to Make Your Phone Charge Faster ➜


While charging your phone via power banks may not be a risk in itself, it is important to understand and look at the different kinds that are available on the market today. Some are totally normal to use, while others can straight up kill your smartphone’s battery.


What should I look for in a power bank to elongate the lifespan of my phone’s battery?

The power bank you choose should be manufactured by an established manufacturer known for adhering to their claims (look out for aggressive marketing tactics). It should feature enough safety standards and requirements to fully charge your device and should be made of robust materials to ensure safe operation.

Does more battery capacity in a power bank mean it’s better?

No, that is certainly not the case. You’ll find power banks priced at $50, and at the same time $200 boasting the same battery capacity. It’s important to factor in the PCB quality, the internal circuitry, damage protection, fast charging, and more when looking for a power bank.

My battery health is reducing fast when charging with a power bank. What do I do?

While most modern power banks don’t damage your battery, it’s important to check what quality of devices you’re using to charge up your phone. Try and use an alternative source for some time and check to see if the issue persists.


Muhammad Qasim

Qasim's deep love for technology and gaming drives him to not only stay up-to-date on the latest developments but also to share his informed perspectives with others through his writing. Whether through this or other endeavors, he is committed to sharing his expertise and making a meaningful contribution to the world of tech and gaming.