[Q] how to run a phone without battery only by connecting charger

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Shrihari007

Senior Member
Apr 17, 2012
574
263
I think the question may be silly but I want to know the procedure for this. can I run the phone directly by connecting only charger and removing the battery...as I keep for downloads of movie over 3g it drains battery damn fast and if its kept charged the battery looses its power. so plz help me out.
 

winlip

New member
Jun 24, 2016
1
0
Using Phone without Battery

I happen to come across this guy from India who has shown in his video how to run your device without inserting battery in it.
Here is the youtube title of the video - Use your phone without a battery....USB phone.....Works for android like charm

This trick specially you can try on the those mobile phones which is very old and moreover you don't find a battery for it.
 

rosemonkey88

New member
Jan 4, 2011
1
2
For Sony Xperia Series Hardware

Try this, i would say it works for most of the Sony Xperia series. only a guess, i have tested only Sony X10, Xperia E, Xperia Z1, Z2. for other models or even poket wifi etc, i would say they are working in the similar way, worth trying. again at your own risk.

do in this way, 3pins on the battery power connector inside the phone, connect the plus to the USB charging port plus(that 5v) - this is because i dont want extra cabling inside the phone, reuse the charging connector on the phone as power supply instead of charging. between the middle pin and the minus , connect a 20-30k resistor, connect the usb charging cable, connect the cable to a 5V power source. the phone will boot without a battery. monitor the fake temperature of the battery shown by a battery monitor app, need to be between a normal working temperature), try and adjust the value of the resistor if necessary.

Pay attention to these :

1. if you think apply 5v power source to a 3.7v battery plus pin, it will damage your phone and make you feel uncomfortable, dont try this at home. you can try 3.7v-4.0 with extra power wiring inside the phone.

2. phone requires very high current(300mA - 1.8A) and varies all the time compared to that a normal charger can provide, dont expect it will boot if u use a "ebay charger" or a PC USB port. i would say , most of the ebay chargers,if not all, will not be able to boot up a phone for current's sake regardless what they claim or be printed on the description. USE A RELIABLE HIGH CURRENT STEP DOWN CONVERTER, get from a powerful and reliable power source (a laptop power charger 19v, up to 3A, for example), keep monitoring the current when you boot the phone. Any car cigarette lighter socket normally can provide enough current, if it fails to boot, check the current your step down converter can provide. The step down converter i m using is just about $6-$7. not expensive one but need to find the right one(i bought more than 10, but only one useful for this purpose, they are all cheap $1-$10).

i came across this issue when i started making my own car onboard GPS system by using an old Sony Xperia X10, then Z1, then later, tested E and Z2 for fun . currently my system evolves to an Android X86 on a normal PC platform bluetooth, wifi and onboard video recording system connected. its all just for fun.

if you are looking for making your onboard phone boot with the engine key, dont need to worry too much about the switch on off, battery charging etc., Another idea is to use or modify a voltage step down converter(12V->5V), make its output voltage vary , say 3v-5.5v by a potentiometer (get it from an old PC speaker), then connect it to the onboard phone as a charger, you dont need to modify you phone, just change the charging voltage so as to the charging current, that means charging the phone while using the phone. if u charge more than you use , then the battery will increase when u drive,if u lower the voltage, the more u drive the more the battery decreases. u never need to take out the phone to charge. of course, you need to automate the phone on off with the engine key, to boot up GPS application automatically etc. i found this very interesting, currently an Xperia Z is running in this way, i found you need to adjust the charger voltage only once for months. theoretically, you have a balance point, always can make when u drive you car, keep the charging equal to your phone using.

happy to share this experience with anyone interested and good luck to everyone coming across this problem.
 
Last edited:

Bojan79M

Member
Nov 22, 2013
10
1
Hi,
just to let you know Lenovo C2 Vibe, it allow's to run without battery. You need battery only for start the phone.
Then the percentage of battery will fall to 0% but phone will still work. It's only one thing, if you turn display off, the phone goes off. You need to restart it (with battery). But if you go to setting for developers and "turn on" option for: display to stay on, when charging will work all the time.
 
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gdroid666

Senior Member
Feb 23, 2016
258
7
OnePlus Nord N200 5G
It should work by taking the protection circuitry from an old battery and take a power bank that uses a lithium cell and connect the + & - of the power bank to the + & - of the battery circuitry.
This way it should trick the phone into thinking it has a fully charged battery installed, plus giving the extra overcurrent protection from both boards.
"protection circuitry"' haha what a joke those things are
it does basically nothing i do not understand why these phones are designed so ****ty
they are literal house fires waiting to happen anyone with common sense designing these things would make it so that the phone itself had it's own protection circuit that makes it manage the battery charging (which the chip in the battery is supposed to do but doesn't) , most of these phones do not seem to have any protection for the battery overcharging like most normal electronic devices did in the past that ran on rechargeable batteries,they had a circuit that charged the battery then when the battery is full it would stop charging it and direct all the power from the charger to run the device and you could run the device on wall power with no battery in it, now most of these phones won't run with no battery in them and even worse is they do not even stop the battery from over charging.
I just used my old galaxy to run a bridge app that runs the battery down quickly ,i plugged it into the charger figuring the people who design these things are not complete incompetent morons with no brains what so ever guess i was wrong to assume such a thing though because within a week of leaving the phone plugged in on the charger with the screen off and the bridge app running in the background the battery has nearly exploded and puffed up like a balloon ,why wouldn't they put decent charge protection in these pieces of crap? why would't they just stop charging the battery when the damn battery is full and why would they make it so it won't run off ac only with no battery in it?none of this makes any sense how do these things even get safety approval?
whoever designs these things is retarded ,once the battery is full the chip should stop charging it and direct the AC power to run the device and if the battery is removed AC power should be directed to run the device, instead if you leave it plugged in it just keeps on running off of the battery instead of running off the charger when there is a battery in it and ruins your battery this makes no sense what so ever
electronic devices never used to be this ****ty until these "smart" phones came out
this **** is not designed right at all, ,when your device is plugged in the charge circuit should charge the battery to 100% and then run the device from the AC power only but instead is runs it from the battery when it is plugged in,now how reetarded is that? it is pointless and it just fries your battery for no reason at all , when they could have just let the battery stay charged and then run the device from AC ,when i charge my tablet and power it down it stays at 100% for months when i boot it up again it is at 100% months later there is no need to make it keep discharing and recharging the battery when it is plugged in but that is exactly how these moron designers have designed these things to operate

oh yeah i see lots of videos of indians just splicing a UBS cable and using the + and - wires connected directly to the battery terminal in the battery compartment on the phone i also have seen videos where the charge circuit from the old battery is used and the power wires from the spliced USB cable put to where the battery connected to the charge circuit

i wonder if it would be possible to just jump the + and - terminals inside the battery compartment of the phone with something, like maybe a capacitor are maybe the charge circuit from the old battery with a capacitor put in place of the battery or some other circuit , so that you could just plug it in like normal and the phone would think there is a battery in it
of course none of this would really be necessary if these things were just designed with any common sense in the 1st place , i swear they do this on purpose to make a market to sell more batteries
because there is no way anyone smart enough to design these things is really that dumb ti make such an oversight or to lack the common sense to see what they do is so retarded
 
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proguru

Member
Feb 9, 2014
25
4
within a week of leaving the phone plugged in on the charger with the screen off and the bridge app running in the background the battery has nearly exploded and puffed up like a balloon

I can confirm this. I also thought that it is safe to leave a phone connected to a charger, thus I left my phone running as a WiFi hotspot, but I was wrong. Now, after a month, I noticed that the battery is badly swollen.
 

eGuru_new

Member
Dec 10, 2016
18
4
Teclast X98 Plus II - no battery

I am using my Teclast X98 Plus II (C2D4) in my car for navigation. I have built it into the dash so I am powering from the car battery via a buck converter connected to the pcb pads previously occupied by the battery pack.
When set to 4.3V, the tablet will boot reliably. I have found that you need a supply that is capable of supplying more than 5A otherwise the tablet will often not boot. This is due to some short-lived peaks in the current draw that cause the output of weaker supplies to droop too low.
Here is a link to the supply I am using (for reference).

https://abra-electronics.com/roboti...vdc-to-12vdc-15a-stepdown-buck-converter.html

It can source up to 14A which sounds like over-kill, but results in very little heat dissipation under normal operation.
 
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latedev

Member
Oct 31, 2016
7
1
Just to dispel a few myths I will as my 2p
Chargers are trickle charge devices so may not work correctly however with a little bit of preparation you can power any phone with a suitable power supply. By suitable I do mean anything that will run the phone without getting too stressed, as in hot. You cannot have too big a supply as long as the correct voltage is applied, which is 3.7 V.
A little about lithium celled batteries. There are either 3 or 4 contacts on the battery, 2 of which (usually the outside 2) are the power connections. Check your phone battery, these should be labelled. On a 3 terminal battery the centre is the battery management signal, which uses the negative of the battery as its earth, whilst on a 4 terminal battery the centre 2 are the battery management connections. These connections are solely down to the battery manufacturer and phone designer.
This is what you call an IIC connection to a circuit board inside the battery, which monitors everything about the battery from day one. I have no idea why this fails given it is placed there to protect the battery and give information to the phone designer.
You can ignore these connections as no battery management is required.

Use a piece of wood the size of the battery, or if you know someone who can solder surface mount components, ask them to attach the battery connections to the USB socket on the phone. Doing it this way gives you added benefits, since PC interface software is available, that can utilise the phone services from a PC. My Phone explorer is the one I use which allows me to send messages or phone from the computer screen, but I am sure there are others which are versatile enough
If you use ply or something similar, you can cut shallow notches in the wood at the position that the battery contacts are on the phone, Get copper strip or flattened wire and wrap this over the edge of the wood and stick down, being careful not to get any glue on the outward facing surfaces. Make sure you mark the wood where the positive and negative terminals are. Attach your wires from your supply or use a suitable USB lead to affect this, and you have a powered phone.
 
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eGuru_new

Member
Dec 10, 2016
18
4
Good writeup by latedev.
The power supply voltage can usually be significantly higher than the 3.7V that has been suggested.
Depending on the battery type, the charging voltage can be up to 4.3V or even 4.4V

If you limit the power supply to 3.7V you will find that the phone/tablet reports that the capacity is about 50% or less.
Since the device is monitoring the current being used, you will find the calculated remaining capacity to decrease with usage.
At some point, you will even receive a false low battery warning and some of your devices (GPS or WiFi for instance) will be turned off to conserve power.

A power supply voltage of up to 4.2V should be safe for your device and will be reported as approximately 90+% charge.

Disconnecting and reconnecting your external power supply will reset the device's power remaining percentage back to the original level.
 

latedev

Member
Oct 31, 2016
7
1
Limiting the supply Voltage may not be a problem and it is a safe value to use. The phone communication with the batter may be an issue, depending on phone manufacturer. If it can't read the battery the phone software may see this as a fault and shut down the phone. Although I doubt that is the case, as many batteries go into extreme failure without a by your leave from the phone.
I have seen others state that the middle connection to the battery is a thermistor, which tbh would be dangerous with Lithium batteries. They do need an active circuit to monitor state of charge. This is usually by what you call a 1 or 2 wire bus and needs software to decode a signal. The phone initiates data transfer then expects an answer. How the phone designer deals with this is the key factor. I did forget to mention the 1 wire bus in the previous answer.Although both types have an active IC in with the battery for monitoring purposes.
Power % is a measured value, so depends on phone software. and reading the battery as previously stated. tbqh I would think this is a fire and forget method on many phones. Software could be, send out for info, if no answer forget about it until next time I ask and leave the battery Voltage indicator alone.
 

nicepants42

Member
Nov 27, 2017
6
0
3.7v doesn't seem to work, even though the battery I'm trying to emulate has only 2 wires.

I have a Moto E 2nd gen model # 1526. The battery is 'non-replaceable' and there are only two wires emerging from the battery that connect to the phone. I can't post links, but if you google XT1526 battery you should see what the thing looks like. Anyway, because there are only two wires connected to the phone, I was under the assumption that simply applying ~3.8v across those two wires (with sufficient amperage) would allow the phone to work. Short answer, it doesn't, and I don't know why or what to do. Long answer:

I purchased a meanwell 150W PSU capable of supplying ~3.2 to 4.2V and controlled by potentiometer. Using this PSU, a breadboard, voltmeter and connectors, I tried operating the phone by supplying ~3.7 through ~4.2V directly into the battery connector, with no luck. I did notice a short voltage drop when trying to power on the phone. The screen would light up briefly (nothing displayed) and then shut off.

Next step, I disassembled the top of the battery and found a small, thin PCB. This board is wired directly to the battery outputs, and has a couple of surface mount things soldered onto it, and also has the two tiny output wires and battery connector that connects to the phone. I then tried wiring the Meanwell PSU to this board where the battery outputs connect, and then connected the battery connector to the phone, and applied the same range of voltage. Still no dice.

So it doesn't appear to be as simple as voltage/current, but I'm not sure what else to try. I have a test PSU from a computer than can supply 5v, 7v, 12v, but those don't seem likely to work, because that would mean that the tiny PCB in the battery is a voltage rectifier, and if that were the case, it seems to me that it would overheat.

Any ideas/suggestions?
 

eGuru_new

Member
Dec 10, 2016
18
4
3.7v doesn't seem to work, even though the battery I'm trying to emulate has only 2 wires.

I have a Moto E 2nd gen model # 1526. The battery is 'non-replaceable' and there are only two wires emerging from the battery that connect to the phone. I can't post links, but if you google XT1526 battery you should see what the thing looks like. Anyway, because there are only two wires connected to the phone, I was under the assumption that simply applying ~3.8v across those two wires (with sufficient amperage) would allow the phone to work. Short answer, it doesn't, and I don't know why or what to do. Long answer:

I purchased a meanwell 150W PSU capable of supplying ~3.2 to 4.2V and controlled by potentiometer. Using this PSU, a breadboard, voltmeter and connectors, I tried operating the phone by supplying ~3.7 through ~4.2V directly into the battery connector, with no luck. I did notice a short voltage drop when trying to power on the phone. The screen would light up briefly (nothing displayed) and then shut off.

Next step, I disassembled the top of the battery and found a small, thin PCB. This board is wired directly to the battery outputs, and has a couple of surface mount things soldered onto it, and also has the two tiny output wires and battery connector that connects to the phone. I then tried wiring the Meanwell PSU to this board where the battery outputs connect, and then connected the battery connector to the phone, and applied the same range of voltage. Still no dice.

So it doesn't appear to be as simple as voltage/current, but I'm not sure what else to try. I have a test PSU from a computer than can supply 5v, 7v, 12v, but those don't seem likely to work, because that would mean that the tiny PCB in the battery is a voltage rectifier, and if that were the case, it seems to me that it would overheat.

Any ideas/suggestions?

If the Meanwell power supply has a current limit adjustment, that may be the cause of the voltage dip on bootup.
Adjust the supply to 4.2V without a load connected and then raise the current limit until you don't see any voltage droop.

Do this without any battery in the phone

btw - What is the model number of the PSU?
 
Last edited:

nicepants42

Member
Nov 27, 2017
6
0
If the Meanwell power supply has a current limit adjustment, that may be the cause of the voltage dip on bootup.
Adjust the supply to 4.2V without a load connected and then raise the current limit until you don't see any voltage droop.

Do this without any battery in the phone

btw - What is the model number of the PSU?
PSU Model: HSP-150-3.8
I glanced at it again yesterday and if there is a current limit adjustment, it isn't obvious. Was thinking 3.8v +/- with 30 amps available should be plenty when I bought it.
 

zeroFILL

Member
Mar 26, 2009
33
1
I have an old LG Optimus G (code F180K) and already made it turn on without the battery. I take out the PCB of battery, connect power 5VDC-2A to PCB and plug it back into the phone. It can turn on and run normaly. I just notice it warmer a bit than usual, but if I decrease voltage or use 1A adapter it cannot boot or just blink the screen then off.
My issue is, phone treats the PCB like a real battery! The battery remaining percent is also countdown to zero and then the phone is off. I cannot use it continuously (I want to use the phone as a nightstand clock).
So is there any trick or program to "freeze" battery percent, or reset battery percent frequently? Please help!
Sorry for my English!
 

thra1982

Senior Member
Jun 22, 2012
164
30
Svendborg
Anyone tried with a LG G3 D855?

It's done with a LG G4 and a quick charger.

I've tried the same procedure on a LG G3, but without luck. Though it wasn't a quick charger, I have tried several chargers. Would that make a difference?
 
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supermaxkato

Senior Member
Feb 21, 2010
192
25
@zeroFILL Here's how to fix the battery percentage going down:
-You have to be rooted
-Use the terminal emulator app
-Type SU (switches from $ to #)
-Type this command to keep the phone at 100%
dumpsys battery set level 100
-Type this command to tell the phone that the charger is plugged in
dumpsys battery set usb 1

Everytime you reboot it reverts to stock settings. So I use a tasker script that runs the above commands on every boot.
I've only tested all of this on an htc desire 510 running 4.4 so these may or may not work on your device.

---------- Post added at 12:41 AM ---------- Previous post was at 12:37 AM ----------

What I'd really like to know is if anyone knows how to still use the USB port to power the phone (instead of hard-wiring to the battery terminals)? There has to be a combination of jumpers, or a resistor to mimic a fake battery, so that we can still use a standard cable and the normal phone connector. Anyone have any ideas?
(Right now I have it working but I had to drill a hole through my back cover and splice a micro usb cable, so I'm hoping for a cleaner method).
 

zeroFILL

Member
Mar 26, 2009
33
1
@zeroFILL Here's how to fix the battery percentage going down:
-You have to be rooted
-Use the terminal emulator app
-Type SU (switches from $ to #)
-Type this command to keep the phone at 100%
dumpsys battery set level 100
-Type this command to tell the phone that the charger is plugged in
dumpsys battery set usb 1

Everytime you reboot it reverts to stock settings. So I use a tasker script that runs the above commands on every boot.
I've only tested all of this on an htc desire 510 running 4.4 so these may or may not work on your device.

I tried those commands but they didn't work. Theres nothing happened. My phone is LG F180 running Android 4.1, rooted. Thanks for your reply! :)
 

SnowFuhrer

Senior Member
Apr 5, 2018
1,622
471
Spirit River
There should be some way to do it with some software. My phone (LG k4 k121) will just power off if I pop the battery out. One time when it froze though, I pulled out the battery and it stayed on. I would like to find a way to run with just the usb cord.
 

Equals1anon

New member
Jul 21, 2018
1
0
Ok here's the solution.

Some phones have a 3 pin power system. Usually the older ones. Most newer phones have a 4 pin power system. Remove battery. Look at the battery to determine the pos and neg pin sides. Get a small piece of wire. Connect the pos and neg pin together where the battery connects. Plug In phone. And wallah... your welcome.
 

SnowFuhrer

Senior Member
Apr 5, 2018
1,622
471
Spirit River
The phone would detect that and not work. Besides, to put a wire between the two would create a short and could fry something. But you could always try. Just don't Blame me if it doesn't work.

Sent from my Samsung SM-A520W using XDA Labs
 

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    @zeroFILL Here's how to fix the battery percentage going down:
    -You have to be rooted
    -Use the terminal emulator app
    -Type SU (switches from $ to #)
    -Type this command to keep the phone at 100%
    dumpsys battery set level 100
    -Type this command to tell the phone that the charger is plugged in
    dumpsys battery set usb 1

    Everytime you reboot it reverts to stock settings. So I use a tasker script that runs the above commands on every boot.
    I've only tested all of this on an htc desire 510 running 4.4 so these may or may not work on your device.

    ---------- Post added at 12:41 AM ---------- Previous post was at 12:37 AM ----------

    What I'd really like to know is if anyone knows how to still use the USB port to power the phone (instead of hard-wiring to the battery terminals)? There has to be a combination of jumpers, or a resistor to mimic a fake battery, so that we can still use a standard cable and the normal phone connector. Anyone have any ideas?
    (Right now I have it working but I had to drill a hole through my back cover and splice a micro usb cable, so I'm hoping for a cleaner method).
    2
    Samsung phone switch on only while external power is given

    For accomplishing this task,
    1) Download the "Auto Boot On Power" app from packagedisabler.com website to your phone.
    2) Install the app.
    This is a great service from packagedisabler team which allows android users to enjoy this amazing feature which was earlier
    available only to the iphone users.

    Use case: In showrooms and exhibitions, all the devices can be switched on and shut down easily.
    output_wbSCk7_1000x1500.gif
    2
    For Sony Xperia Series Hardware

    Try this, i would say it works for most of the Sony Xperia series. only a guess, i have tested only Sony X10, Xperia E, Xperia Z1, Z2. for other models or even poket wifi etc, i would say they are working in the similar way, worth trying. again at your own risk.

    do in this way, 3pins on the battery power connector inside the phone, connect the plus to the USB charging port plus(that 5v) - this is because i dont want extra cabling inside the phone, reuse the charging connector on the phone as power supply instead of charging. between the middle pin and the minus , connect a 20-30k resistor, connect the usb charging cable, connect the cable to a 5V power source. the phone will boot without a battery. monitor the fake temperature of the battery shown by a battery monitor app, need to be between a normal working temperature), try and adjust the value of the resistor if necessary.

    Pay attention to these :

    1. if you think apply 5v power source to a 3.7v battery plus pin, it will damage your phone and make you feel uncomfortable, dont try this at home. you can try 3.7v-4.0 with extra power wiring inside the phone.

    2. phone requires very high current(300mA - 1.8A) and varies all the time compared to that a normal charger can provide, dont expect it will boot if u use a "ebay charger" or a PC USB port. i would say , most of the ebay chargers,if not all, will not be able to boot up a phone for current's sake regardless what they claim or be printed on the description. USE A RELIABLE HIGH CURRENT STEP DOWN CONVERTER, get from a powerful and reliable power source (a laptop power charger 19v, up to 3A, for example), keep monitoring the current when you boot the phone. Any car cigarette lighter socket normally can provide enough current, if it fails to boot, check the current your step down converter can provide. The step down converter i m using is just about $6-$7. not expensive one but need to find the right one(i bought more than 10, but only one useful for this purpose, they are all cheap $1-$10).

    i came across this issue when i started making my own car onboard GPS system by using an old Sony Xperia X10, then Z1, then later, tested E and Z2 for fun . currently my system evolves to an Android X86 on a normal PC platform bluetooth, wifi and onboard video recording system connected. its all just for fun.

    if you are looking for making your onboard phone boot with the engine key, dont need to worry too much about the switch on off, battery charging etc., Another idea is to use or modify a voltage step down converter(12V->5V), make its output voltage vary , say 3v-5.5v by a potentiometer (get it from an old PC speaker), then connect it to the onboard phone as a charger, you dont need to modify you phone, just change the charging voltage so as to the charging current, that means charging the phone while using the phone. if u charge more than you use , then the battery will increase when u drive,if u lower the voltage, the more u drive the more the battery decreases. u never need to take out the phone to charge. of course, you need to automate the phone on off with the engine key, to boot up GPS application automatically etc. i found this very interesting, currently an Xperia Z is running in this way, i found you need to adjust the charger voltage only once for months. theoretically, you have a balance point, always can make when u drive you car, keep the charging equal to your phone using.

    happy to share this experience with anyone interested and good luck to everyone coming across this problem.
    1
    Just btw., how difficult would it be to have the battery /hardware recognize when charge capacity is at 100% and have it switch-over to a mechanism that powers the device directly.

    Likewise, such a system should allow for a mobile device to function normally w/o a battery, as there are decades-old laptop computers which can do the same.. I don't get it, whatever. :/

    Same as with having: universal 1) batteries and /or 2) print cartridges (refillable, as well, ofc.)

    By now, we would have: 1) absolutely amazing (!), brilliant battery technology, if it weren't proprietary and 3rd-parties were able to manufacture batteries for all sorts of devices and be able to invest profits into r&d and 2) probably, world-wide pollution numbers could decrease by (some crazy amount, like) 1% if all, those, obsolete cartridges weren't being discarded.

    Not meaning to mix apples and oranges, but the cause and effect is completely the same: a) greed and b) failure, blah! :f
    1
    very helpful

    this forum thread was helpful! :) thanks!