How To Jump-Start Phone Battery (No-Budget Hack)

Few days after Jasmina’s Sony Xperia Z charger broke, I had another unpleasant surprise. I woke up to a dead phone and no amount of charging, trying to turn it on, putting the battery in and out, helped…

Things to try before you jump start your battery

  1. Turn the phone on by pressing/long-pressing the power button
  2. Take the battery out. Press and hold the power button for at least 30s.
  3. Try a new battery. Borrow from a friend who has the same phone.

Why this can help

First point is self explanatory. If your phone turned off because of a glitch or something, this turns it back on, voila!

Second point might seem a bit weird to most. You obviously won’t turn on the phone while it has no power supply. Good thing this isn’t the point here. This step discharges residue charge from your phone’s electronic components. This also works for laptops and I used it to revive quite a few of them inspiring statements like “It didn’t work before, I swear!”. I know, I believe you 🙂

Third point, tried after second, makes sure it’s a problem with battery and not the phone. You can also try your battery in your friend’s phone.
I didn’t have a spare battery to try with, so I used the cable described later in article and connected the red and black directly to the appropriate pins inside of the phone. My Samsung S3 turned right on, so that ruled out problems with the phone itself.
If you’re in the similar situation be careful, the right pins will depend on the phone you have. My battery’s plus and minus pads were marked so I just followed and saw witch pins in the phone they touch. You can follow the same idea to figure out where your phone’s plus and minus pins are.

Why your battery plays dead

I’m talking about lithium-ion battery (sometimes called Li-ion battery or LIB), which are most common batteries in phones these days.

They can go unstable and “boom” if they get too discharged. To prevent that doodoo, engineers put electronics in place with some smarts in them. If the battery voltage drops below a certain point, to prevent further discharge, they disconnect the cells from the battery pads completely. Thumbs up for safety!

So why can’t you charge it?

Your phone has a battery charger or else you’d have to take your battery out every time to charge it. Convenient!
In order for that charger to work, it needs electricity. It gets its electricity from the battery, which currently puts out 0V.

The Hack (this is what you’re here for)

All you need is a spare USB cable and a charger (or a laptop, play station, smart TV…).

  1. Cut the USB cable.
  2. Skin 5mm of red and black wires.USB cable wires
  3. Twist the exposed end of each wire.
  4. Plug the cable into charger.
  5. Place the black wire (-) to the minus of the battery.
  6. Place the red wire (+) to the plus of the battery.
  7. Hold in place manually for a couple of minutes.
  8. Put the battery back into the phone.
  9. Plug the phone into the charger.

Your phone should soon start charging. If it doesn’t, try again, make step 7 longer.

Jump starting a phone battery

Why this works

USB gives 5V which is above the normal Li-ion battery voltage (3.7V or 4.2V). This charges the battery enough to be briefly above the cut-off voltage. That’s just enough to start your phone’s charger and allow it to continue charging the battery until full.

I’ve been using and charging my phone normally since then. I also don’t allow my phone to die from empty battery. Lesson learned 🙂

53 thoughts on “How To Jump-Start Phone Battery (No-Budget Hack)

        1. Hi Alex,

          I’m not exactly sure what you mean by “cable strip”. What this does is, it charges the battery a little bit “forcibly” to (temporarily) raise the voltage enough so phones charger can recognize it and continue charging it.

          If your battery has the same problem, you should be able to boost it the same way. Be cautious and happy hacking 🙂

  1. hey bro i am gonna use this trick with my canvas 2 and just hope that it works and one more thing that my phones upper part gets hot i there i any current in the phone. i u can help me or the same!!!

    1. Hi Dev,

      There is more than one reason why phone might be getting hot.
      When it’s charging, there is electrical current flowing from the wall outlet through your phone to the battery.
      Another case is when you’re using it heavily, your processor uses more power and more current flows through it. That’s why your phone depletes faster and gets hotter.

      These are both normal use cases and unless it gets too hot, it doesn’t represent a concern.

      As explained in the article, jump-starting a phone battery might be needed if you can’t get your phone to charge the battery.
      If your phone battery charges, just gets hot, jump-starting is not going to help.
      Charging with lower current might help, but your battery will take more time to charge.

      I hope this helps.

      Cheers, Zvonimir

  2. I’m sorry to be too late but I actually have a phone in which the battery can’t be removed. How can i jump start this one?

    1. That’s a tough one and might not be possible without opening the phone.
      How did you identify that battery is the problem?
      What’s the model of the phone?

    1. iPod 5g has a lithium ion battery and if you get to it, it should perform as the article explains. Exercise caution and don’t do anything you’re not prepared to take responsibility for 😉

      Good luck!

  3. Hi! I can see that my handphone has been fully charged. But i can’t turn in on again. It just shown fully charge , and that’s it all. What should i do?

  4. Wow! Used it for an old Nokia I had lying around. Can’t believe I didn’t think of this considering I’m usually pretty good at this stuff! Great hack dude! You’re smart!

    1. There should be no difference. You can trying boosting it for longer (couple of minutes or more, depends on the state of the battery; it needs enough juice to be able to take care of its charging process when you use original charger) and/or upping the voltage/current a bit.

    1. Hey Peter!

      To my knowledge devices with built-in batteries don’t give direct access to battery (why would they) and you access the battery only through the charging system you’re trying to circumvent.

      Solution for that would be to open the device to get to the battery. There’s a whole new set of things to watch out there, it’s depending on the device and it’s much riskier since you can break the device. Good news is the same principle applies once you have the battery in your hands.

      I don’t have any links right now (I’m not on my computer) but ifixit should have the tools you need to get in and you can order them online.

      If your device is bricked and you can’t take it to the shop, you might as well have a little fun with it and have a chance of fixing it, but be careful and don’t do anything you’re not comfortable with.

    1. Well, best way then would be to use a voltmeter to determine polarity (where’s the plus and where’s the minus.)
      If you don’t have a voltmeter, you could use an LED with a resistor in series to determine polarity.
      What other electronic components do you have around?

    1. Depends. It’s highly unlikely, but I can’t rule it out. Likelihood goes up if battery is physically damaged.
      Also, remember Galaxy Note 7? So, sure, but I wouldn’t bet on it.

  5. using LG my phone can’t turn on when I power it on don’t no if the battery fault or phone but the battery have power unable to turn it on plss help

    1. If you’re sure your battery is full, then it’s probably something wrong with the phone or phone’s connection to the battery.

      If you’re not sure, then it might mean that your battery is overdepleted and steps in this article might help you.

      Steps here won’t work if you can’t remove the battery from the phone.

  6. I had remove my battery to charge with universal charger cuz my charging system not working when it finish charging n I plug it in my phone it can’t power on again that how the problem start

    1. It’s possible that your battery didn’t actually charge, or that something’s wrong with getting the power from the battery to the phone, or that something’s wrong with the phone itself.

      I can’t really tell based on the information you provided.

      If you’re really, really sure that the battery is charged, then it’s probably one or both of the latter two.

        1. I assume by terminal you mean contacts/connectors?
          You’ll have to find where plus and minus connectors for that specific battery are if it’s not obvious.

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