Swollen battery? Expensive to replace? Make your smartphone work without battery!


Batteries in older phones can swell after going past their charge cycles. Batteries also swell if left unused for an extended period of time. Although the battery can be replaced for some phone models, the exorbitant price of battery replacement discourages many phone owners from doing so.

Also, these phones are usually a few years old and firmware updates may have already stopped. This is the main reason not to spend money on a new battery on an outdated phone. Wouldn’t it be good to run the phone with no battery at all?

Why do batteries swell in the first place?

Charge and discharge cycles cause the lithium battery electrolyte to produce gas inside the battery. A swollen battery is a safety risk, it can overheat while charging, catch fire and even explode. It is wise to replace these batteries immediately.

A swollen battery

The problem is that phone manufacturers don’t use the same battery types on different phone models of their own brand. This results in replacement batteries becoming unavailable after a few years.

One way around this problem is to get a replacement battery from a third-party manufacturer, but most third-party batteries have a poor safety record and can be risky to use.

What else in the phone works?

The battery may be exhausted, but the smartphone still has other functional components. Despite this, most smartphones have no resale value and end up in electronic junkyards.

There is still life in these smartphones if they are reused. How much life?, you may ask. In fact, many years. Being electronic components, the processor; memory and display have a long life.

The internal components of a smartphone

Try it first with ease

Remove the battery from the smartphone or tablet, plug in the USB charger cable and turn on the device. Unfortunately, most devices shut down abruptly during the boot process because they detect the missing battery. A few of them will complete the boot sequence and work fine. This is observed especially in tablets. If your device works like this, you don’t have to do anything more: you’re in luck. Otherwise, you have to fool the device about the presence of a battery and buy your luck with logic.

A batteryless tablet running from a power bank

Overview of the test phone

This Android smartphone is manufactured by Alcatel. The battery has already swelled, but it still works. A replacement battery is hard to find since the phone was made a few years ago. It’s reasonably fast and has a perfectly functional screen. It runs Android 5 Lollipop, an outdated operating system. It doesn’t receive any firmware updates, but the Play Store still works fine and many popular apps are still compatible.

Smartphone with running Android Lollipop and a 3.8 volt battery

A 3.8 volt battery is in the smartphone, so you should use a DC power source with a similar voltage. Luckily, the USB power supply is 5 volts and is fine for this purpose. USB chargers and power banks can do the job.

However, smartphones have varying current demand. An example would be the activity of playing a resource-intensive game with the screen brightness at maximum. In such a case, the battery can instantly deliver the additional amperage. The chosen 5V USB power source, whether an adapter or a power bank, should have a decent current rating to sustain the peak demand. Power banks between 2.4 and 3.4 amps work well, depending on the screen size of the smartphone.

A 5 volt 3.4 amp USB adapter

A swollen battery barely fits in its compartment. The test battery has four pins. Two of them are marked as positive and negative; the other two are unmarked. There are an equal number of pins on the phone; only two of them will be used for power. The other two are used to detect the battery level on some phone models.

A swollen battery unable to fit into the phone compartment

The idea is simple: cut a USB cable and solder it directly to the pins of the phone. Since the polarity is already marked, we don’t need a multimeter. Remove the insulating sleeve from the USB cable and solder the red wire to the positive pin and the black wire to the negative pin. Often there are two extra data wires in the USB cable. They are not necessary and can be cut.

Cut a USB cable and splice the wires

Use a good quality usb cable, one with heavy gauge wires, as it has to carry a large amount of current. A cable rated for 3.4 amps and above at 5 volts is what you need; usually the cables that come with power banks are fine.

Phone battery pins soldered to USB wires

Connect the other end of the USB cable to the USB power adapter and turn on the device. Your smartphone should work fine without needing a battery. It will also work with a power bank.

Phone working without battery and powered only by the USB adapter


Remember that before soldering, you can test the configuration by temporarily connecting the wires using alligator clips.

Phone battery compartment with alligator clips connected to battery pins

If it doesn’t work as expected, here are some troubleshooting tips:

  • The phone does not turn on: Check the solder.
  • The phone turns on but turns off: Check the amperage of the USB power adapter and the quality of the cable.
  • The phone turns on but complains about the temperature of the battery: Since there is no battery in the phone, this is a pseudo warning. It is indicated in the status bar; pay no attention to it.
  • Phone turns on, complains of bad battery and turns off: Do you remember the two unmarked pins on the battery? Some smartphones use them to check the battery status. Measure the pin voltage on the battery. Solder a resistor between the positive pin and the corresponding sense pin on the phone to create a voltage drop. The exact resistor to use depends on the battery readings.

A phone with an AC adapter and resistor

Applications for your phone without battery

You now have a working device. However, since manufacturers don’t release updates after a few years, it’s probably stuck with old firmware. This is especially true with Android devices that aren’t made by Google. A quick check on Play Store shows that many apps are still available for your device.

Although the apps are there, think carefully about what needs to be installed. If there is a security issue, the old firmware becomes vulnerable. As a general rule, you should avoid this combination: “Device connected to the Internet and equipped with applications that have collected sensitive data”.

The other constraint is that the modified device is not very portable: it is cumbersome to carry it in the pocket with an external battery. This limits the type of apps that can be used, but luckily there are plenty that suit the purpose. Here are a few :

Ping Monitor

You can use this app to ping any IP address. This is a quick monitor that displays the status of devices on the network, for example to check if the network printer is on/off.

Phone displaying the ping monitor pro app while it monitors network devices

Wi-Fi Analyzer

Wi-Fi drops on certain days? The neighbours’ signal may interfere with yours. Use of data from any of these Wi-Fi scanner appsyou can quickly decide whether to change channels or not.

Google Authenticator

If you want stronger security, you can force apps to ask you for two-factor authentication every time. Instead of reaching out to your primary phone, you can have a live display of 2FA codes on the saved one. There is one caveat though: if your phone restarts, you need to set the clock again. The reason is that it has no battery.

Phone displaying the Google Authenticator app

YouTube or Google Analytics monitor

If you have a website or manage a YouTube channel, you can monitor visitors using these apps. Live data can provide insight into trending content and help you adjust suggested content accordingly.

Google Maps GPS Navigator for Cars

If you’re using a phone in a car for navigation and you’ve placed it towards the windshield, you’ll notice that it gets quite hot on a sunny day. Heat is a risk for the phone battery. Now that you have completely removed the battery, you can safely use the phone. You can even use it as a continuous recorder.

Phone displaying Google Maps attached to the dashboard of a car and powered by a USB cable

Let your phone run its full life cycle

Battery replacements are very cost effective for smartphone manufacturers. Discouraging easy replacement started with a sealed back cover. It could end with a smart AI chip on the battery as a backup. This will practically lock the phone to the manufacturer’s battery and render it useless without a battery.

Now that you know how to operate a smartphone without a battery, your modified device will serve you for many years to come. It will most likely fail after its flash-based ROM exceeds write cycles; you can then send it for recycling free of charge.


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