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[Q] HELP! magician is not booting after battery drain

i have my magician battery drained and now it is not booting.
Even if I charge it in long hours still no luck to revive it.
I used Cotulla's O5 (WM6.5 for 64mb ram).
Anyone familiar with the issue? Thanks!

I had a Magician like that. Battery had to be shocked to restore it because leaving it drained for a long time caused internal shorts. To shock it, I used a variable 25V power supply applied to the battery contacts very briefly which makes a spark. I did that several times until the spark is smaller and the battery shows some voltage. This trick also works for other rechargeable batteries that refuse to charge.
Sometimes with Magician, it's not an internal battery short, but that the battery voltage is below a charging threshold. In that case, I used small wires to attach to the + and - battery terminals with the battery in the phone, and attached a variable power supply to raise the voltage to around 3.7V under load so that the phone will boot with the dead battery. Once it is booted and the LED is orange to show that it's charging, I remove the power supply and it will stay charging till the battery is full.
You could kill your phone doing this wrong and I don't know what equipment you have access to, but these are things that have worked for me. Although the simplest way is just to buy a new battery.

@GnatGoSplat
hi mate, this is really helpful!

GnatGoSplat said:
To shock it, I used a variable 25V power supply applied to the battery contacts very briefly which makes a spark. .
Click to expand...
Click to collapse
With 25V power supply you can burn battery protection electronics inside in battery and it is possible in that case to overcharge the LiOn battery in next charge cycle and the end it can EXPLODE. In future you can try to apply 5V for little long time and you will achieve same results without any danger to burn battery electronics
Hi arjaylight
Before few days I have same problem with drained new Magician battery. I charged it for little time but the same results as yours, after hard reset the device boot normally.

That depends on the cause of the battery not charging. If battery voltage has fallen below charging thresholds, then applying 5V for a long time should work. If battery won't charge because of internal shorts, 5V will not burn off the internal shorts and the battery will just get warm. To blow out internal shorts, you need a much higher voltage across battery terminals for a very short time. Generally, you should just dispose of shorted batteries as you are correct that they could explode with any attempt to squeeze more life out of them.

Many People used a 9V Battery Block.
Connect only short but frequently ! After ca. 10 Shots maybe u have Luck.
I successfully make that with 2 Sony Ericsson Batterys from K800i.
Is the same Problem : Undervoltage or a little internal short.
Be carefull and patient !

battery drain
thanks for all your inputs.
im trying to find power suplly bu i think what is readily available is the 9v battery block. thanks moto26.
could you explain in details how you did this. 10 shots but how about the intervals? 5secs?

just a side note, after doing all of this if you find that it doesn't work for whatever reason. I found that the dealextreme batteries for the magician hold their charge well and they are very cheap compared to ebay etc.

Useful Battery Information and Calibration

Here is some information that should be useful to everyone in one way or another if not then you should have told us your secret months ago. lol
A Li-ion batteries life is on a time clock from the day it's produced and how it is used, maintained and the number of cycles it goes through reduces it's life. Even when not being used at all the clock is ticking and life is shortening.
So if any of you are like me I know many of you are far worse than me when it comes to the amount of stress put through it with flashing and extreme general use. Hopefully this will shed some light for us as to what we can do to try and prolong the life of our batteries.
The majority of the following information is from the book “Batteries in a Portable World – A Handbook on Rechargeable Batteries for Non-Engineers” (2nd edition) and Battery University™
Special thanks to the books author and sponsor of Battery University™,
Isidor Buchmann
CEO and Founder, Cadex Electronics Inc.
How to Prolong the Life of Li-ion Batteries
Battery wear-down on lithium-based batteries is caused by two activities: actual usage or cycling, and aging. The wear-down effects by usage and aging apply to all batteries but this is more pronounced on lithium-based systems.
The Li-ion batteries prefer a shallow discharge. Partial discharges produce less wear than a full discharge and the capacity loss per cycle is reduced. A periodic full discharge is not required because the lithium-based battery has no memory. A full cycle constitutes a discharge to 3V/cell. When specifying the number of cycles a lithium-based battery can endure, manufacturers commonly use an 80 percent depth of discharge. This method resembles a reasonably accurate field simulation. It also achieves a higher cycle count than doing full discharges.
Simple Guidelines
Charge the Li-ion often, except before a long storage. Avoid repeated deep discharges.
Keep the Li-ion battery cool. Prevent storage in a hot car. Never freeze a battery.
Avoid purchasing spare Li-ion batteries for later use. Observe manufacturing date when purchasing. Do not buy old stock, even if sold at clearance prices.
Hints to long battery life
3.92V/cell is the best upper voltage threshold for cobalt-based lithium-ion. Charging batteries to this voltage level has been shown to double cycle life. Lithium-ion systems for defense applications make use of the lower voltage threshold. The negative is reduced capacity.
The charge current of Li-ion should be moderate (0.5C for cobalt-based lithium-ion).The lower charge current reduces the time in which the cell resides at 4.20V. It should be noted that a 0.5C charge only adds marginally to the charge time over 1C because the topping charge will be shorter. A high current charge tends to push the voltage up and forces it into the voltage limit prematurely.
Memory Myth or Fact?
Lithium batteries are not affected by memory, but the chemistry has its own peculiarities. Current inhibiting pacifier layers affect them through plate oxidation. This degenerative effect is non-correctable on a lithium-based system
Calibration
A more serious issue is maintenance requirements, better known as capacity re-learning. This procedure is needed on a regular basis to calibrate the battery.
Why is calibration needed?
The answer is in correcting the tracking errors that occur between the battery and the digital sensing circuit during use. The most ideal battery use, as far as fuel-gauge accuracy is concerned, is a full charge followed by a full discharge at a constant 1C rate. This ensures that the tracking error is less than one percent per cycle. However, a battery may be discharged for only a few minutes at a time and commonly at a lower C-rate than 1C. Worst of all, the load may be uneven and vary drastically. Eventually, the true capacity of the battery no longer synchronizes with the fuel gauge and "a full charge and discharge are needed to ‘re-learn’ or calibrate the battery."
How often is calibration needed?
The answer lies in the type of battery application. For practical purposes, a calibration is recommended once every three months or after every 40 short cycles.
What happens if the battery is not calibrated regularly? Can such a battery be used in confidence?
Such a battery is able to function normally, but the digital readout will be inaccurate. If not corrected, the fuel gauge information simply becomes a nuisance.
Just Tell Me WTF I Should Do!
Charge your battery as often as possible, partial discharges are actually better for your battery
Once your battery is charged to 100% avoid leaving it plugged in any longer if you are not using a OEM charger.
Your battery should never get hot from charging if it does this is a sign it may be damaged.
If fuel gauge starts acting up calibrate your battery.
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
There is so much more that it's mind boggling but I think this covers the main parts and beyond for everyone. So far it appears that the bump method is not necessary nor are the numerous other steps.
I can only laugh when I think that the reason the method of calibration I was using was actually working is due to the fact that the "wipe batt stats, drain battery completely and charge to 100%" is basically the last step and all that is essentially needed.

3 hours? That's it? I thought whenever I charged from empty to full when it's off it's longer.. I should time it.. hmm

darkamikaze said:
3 hours? That's it? I thought whenever I charged from empty to full when it's off it's longer.. I should time it.. hmm
Click to expand...
Click to collapse
I removed the time completely since some may vary. But the 3 hours is how long it should take to charge on a standalone battery charger. So rather than confuse or have questions it's better without it.

Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.

Battery Stats
Since this is the first time i had a really good battery life. I would like to share it with everyone. Please see the attached screen shots.
I am using Darky's 9.1 with SuckerPunch's 1280/500 Kernel and TLJL3 modem.
I hope this will help anyone trying to get more battery life out of their Captivate.
Thanks,

CuriousTech said:
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
Click to expand...
Click to collapse
Thanks Curious appreciate it and thanks for the additional info.

I had some other random thoughts about the calibration because I keep seeing so many posts daily.
For example "I installed a new kernel 15 minutes ago, recalibrated and the battery drain is horrible." or "After a few charges it lasted longer."
I don't think people get the idea of calibration. Recalibrating determines the capacity of the battery to convert to a % full gauge. To do that you need to fully charge until the "Battery full. Unplug charger." notification, and not rely on the display and unplugging as soon as it hits 100%. That's the inaccurate display that you're trying to calibrate.
Think of it like having an opaque container and a teaspoon. You think the container can hold 100 teaspoons, so you stop filling at 100. All you can get out of it is 100 until you try to fill until it tops off and then count how many come back out.
The phone works the same way. It has an ammeter that monitors the charge current and drain current from the battery from the time you unplug it until it shuts off and remembers that total as the capacity. Unless it's recharged in the middle which voids the data.
After that full discharge, it should stay pretty accurate even with partial discharges. At least until the next rom/kernel flash which wipes it out. At that point (I assume) it uses a simple voltage level and some relative amps drawn to display the gauge, instead of the smarter method of keeping a constant value of mAh by adding when charging and subtracting when draining to know exaclty how full the battery is.

CuriousTech said:
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
Click to expand...
Click to collapse
hm. so if the phone switches to external power when the charge is full, is it okay to leave my phone plugged in once it's done charging? or is it just the fact that the battery is holding a full (4.2V) charge for a long time that's bad for its health?
in any case, useful post! i knew there were ways to preserve the life of li-ion batteries, but was never well-versed on the details.

Yes to both. Once the battery is fully charged, the charge circuit stops completely. It doesn't even need to trickle charge, so leaving it plugged in doesn't hurt anything.
Once the charge is complete the voltage isn't being held at 4.20V so it can come back down a little. I think BatteryUniversity generalizes becuase there have been many different designs over the years that weren't as good as what we have now, and some may have trickle charged their Li-Ions which shortens the life.

Which is it that wipes the battery stats, ROM or kernel? or is it both?

CuriousTech said:
Yes to both. Once the battery is fully charged, the charge circuit stops completely. It doesn't even need to trickle charge, so leaving it plugged in doesn't hurt anything.
Once the charge is complete the voltage isn't being held at 4.20V so it can come back down a little. I think BatteryUniversity generalizes becuase there have been many different designs over the years that weren't as good as what we have now, and some may have trickle charged their Li-Ions which shortens the life.
Click to expand...
Click to collapse
One word of caution though is to ensure that you are using an OEM charger. Battery University recommends that you unplug once capacity is reached but perhaps this is a general statement for Li-ion batteries as you state.

zerkai said:
Which is it that wipes the battery stats, ROM or kernel? or is it both?
Click to expand...
Click to collapse
Both. The first thing in a ROM flash script is to format all the partitions, so that means the batterstats.bin file is erased. When flashing a new kernel the file gets reset by some other means. No idea what. It could be CWM.

Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
My noob question is, how do you delete the battery stats?

iNFRiNGE said:
One word of caution though is to ensure that you are using an OEM charger. Battery University recommends that you unplug once capacity is reached but perhaps this is a general statement for Li-ion batteries as you state.
Click to expand...
Click to collapse
What happens when you introduce the variable of occasional car charger use?

Sanctus Peregrinus said:
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
My noob question is, how do you delete the battery stats?
Click to expand...
Click to collapse
the file is located at /data/system/batterystats.bin . you'll need a file browser with root access (i use root explorer, a paid app). make sure you mount the storage as read/write or you won't be able to delete the file.
after that, reboot your phone and it will rebuild the batterystats file.
***disclaimer: be careful doing this. if you delete a crucial file, you risk messing up or bricking your phone. such is life.

Nice write up with alot of interesting information. I have never calibrated my battery but will have to try it out. Thanks for posting.
Sent from my SAMSUNG-SGH-I897 using XDA App

I'm not positive of this, but I don't think batterystats.bin holds any battery capacity or health info. I was looking at BatteryManager and it looks like a database of processes and what they use only. But there is info somewhere that gets lost easily, which is the capacity and current amount consumed.
I've been skipping the delete of that file (using CWM) and have noticed that it recalibrates fine anyway. This coming from the point of dropping just after unplugging, which is a good indication that the info is gone.
It doesn't matter if you use a car charger, USB, or AC. The phone has the actual smart charger in it, the external connection is just the power supply. The chip inside regulates and monitors the charge.
So think of it this way. The charger knows when the battery is empty or full, and measures what goes in and comes out. So to know the capacity, it has to go from full to empty. That's really all there is to it. Just wait for the real "Battery full" before unplugging.

[Q] How to recharge the over-discharged battery?

Hi all.
I've over-discharged my stock battery and now it doesn't charge. It lights up green as soon as I plug the charger. I've tried different chargers but didn't help.
I've made this using short circuit so don't think it's related to Sensation. You may ask why I tought over-discharging may solve the touchscreen issues. Don't know if it's solved because phone doesn't open.
Do you have any advice to restore the battery rather that getting a new battery? I've already ordered new battery though.

Certain laptop battery manufacturers use a circuit which stores battery charge information, but is itself, "kept alive" by the residual current in (even a dead) battery.
I've seen the case on a number of times that discharging below the "allowed" level causes this circuit to fail, thus the communication between battery and device is incorrect, inaccurate or, at worst, not there at all.
(this is why there are more than just + - on your battery)
You could find the correct recharge rate for the battery - current and voltage - and charge it manually, and hope that said 'battery state circuit' comes back to life, but honestly, I think you'll be, as they say, SOL.
I've had perfectly good laptop batteries, holding a full charge, having a great discharge rate, but the laptop would refuse to accept it, just because of this little circuit.
WARNING: Charging / over charging / charging in a way other than in accordance with the original device literature can VERY likely cause the battery to fail completely, including, but not limited to FIRE or EXPLOSION! DO NOT PROCEED UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING. LiPo (and LiIon for that matter) are EXTREMELY DANGEROUS when used wrongly!
All the above said, have fun, don't blow yourself up, and let us know how you get on. Also, from a personal point of view, I'd be interested to know the 'technical reasons' behind the thought that over-discharging could solve the touch-screen problem - can you remember where you got the info originally?

Figure_desire said:
Hi all.
I've over-discharged my stock battery and now it doesn't charge. It lights up green as soon as I plug the charger. I've tried different chargers but didn't help.
I've made this using short circuit so don't think it's related to Sensation. You may ask why I tought over-discharging may solve the touchscreen issues. Don't know if it's solved because phone doesn't open.
Do you have any advice to restore the battery rather that getting a new battery? I've already ordered new battery though.
Click to expand...
Click to collapse
wtf? did you shortcut the battery or the phone? if shortcut the battery it my be blown. Anywyas you could try jump charging it, unplug and plug it in fast, or put it in a outlet which has a switch and try toggling it on and off for some minutes, you may be able to jump it up to the voltage it needs to start charge

niddnet said:
Certain laptop battery manufacturers use a circuit which stores battery charge information, but is itself, "kept alive" by the residual current in (even a dead) battery.
I've seen the case on a number of times that discharging below the "allowed" level causes this circuit to fail, thus the communication between battery and device is incorrect, inaccurate or, at worst, not there at all.
(this is why there are more than just + - on your battery)
You could find the correct recharge rate for the battery - current and voltage - and charge it manually, and hope that said 'battery state circuit' comes back to life, but honestly, I think you'll be, as they say, SOL.
I've had perfectly good laptop batteries, holding a full charge, having a great discharge rate, but the laptop would refuse to accept it, just because of this little circuit.
WARNING: Charging / over charging / charging in a way other than in accordance with the original device literature can VERY likely cause the battery to fail completely, including, but not limited to FIRE or EXPLOSION! DO NOT PROCEED UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING. LiPo (and LiIon for that matter) are EXTREMELY DANGEROUS when used wrongly!
All the above said, have fun, don't blow yourself up, and let us know how you get on. Also, from a personal point of view, I'd be interested to know the 'technical reasons' behind the thought that over-discharging could solve the touch-screen problem - can you remember where you got the info originally?
Click to expand...
Click to collapse
This is my second unit and it has touchscreen problems too. I'm not an expert but here is why I did that.
My phone was working normally and had %20 battery left. I went outside and didn't have extra battery or charger so I've used my friend's USB cable and lapto to charge it. After it reached to 44% I unplugged it and saw touchscreen issues started. I've searched and remembered some advices from XDA like discharging and charging may solve it so I gave it a try but it didn't help. Then tried over-discharging and charging but stock here.
What do you mean by charge it manually?

Utking said:
wtf? did you shortcut the battery or the phone? if shortcut the battery it my be blown. Anywyas you could try jump charging it, unplug and plug it in fast, or put it in a outlet which has a switch and try toggling it on and off for some minutes, you may be able to jump it up to the voltage it needs to start charge
Click to expand...
Click to collapse
I did short circuit the battery I know sounds crazy but I'm sick of touchscreen issues. Are you saying that I may try connecting it an appropriate charger's output directly like + > + , - > - ?

I'm saying, chances are, it's wrecked. You shouldn't really discharge batteries by short-circuit - that puts massive stresses on the structure of the cells in the battery and probably completely ruins it.
It can also cause excessive heat, which can lead to nasty things happening.
Recharging the battery by connecting + to + and - to - is theoretically possible, however, to do this SAFELY, you would need to know the manufacturer's recommended charge rate, times, voltages etc. They differ greatly.
Do it too slowly, and you just result in a very inefficient trickle-charge, which can sometimes do more harm than good....
Do it too fast - cells in the battery become gaseous, the gas vents, and you have fiery explosions... also not good.
Seriously - I would strongly recommend against playing with it. If you want to see what CAN happen when it goes wrong, YouTube it!!

http://www.youtube.com/watch?v=z3o_2mwRPdw
Insane amounts of energy stored in these batteries

niddnet said:
I'm saying, chances are, it's wrecked. You shouldn't really discharge batteries by short-circuit - that puts massive stresses on the structure of the cells in the battery and probably completely ruins it.
It can also cause excessive heat, which can lead to nasty things happening.
Recharging the battery by connecting + to + and - to - is theoretically possible, however, to do this SAFELY, you would need to know the manufacturer's recommended charge rate, times, voltages etc. They differ greatly.
Do it too slowly, and you just result in a very inefficient trickle-charge, which can sometimes do more harm than good....
Do it too fast - cells in the battery become gaseous, the gas vents, and you have fiery explosions... also not good.
Seriously - I would strongly recommend against playing with it. If you want to see what CAN happen when it goes wrong, YouTube it!!
Click to expand...
Click to collapse
Yesterday I connected the battery which is stock 3.7 V to the my digital camera's charger which is 4.25 V, 0.25 A, 50-60 Hz with cables for 6 hours but didn't work. BTW, stock charger is 5V, 1 A and 50-60 Hz.
Can I try jump charge with this camera's charger? If I can, how fast should I connect and disconnect the cable?

That's exactly what I'm talking about.
It should be noted that the Sensation stock battery is LiIon, rather than LiPo, but the effects can be very similar, and just as disasterous if that happens when your battery is in the vicinity of.... anything!!!

I think it's dead mate =/ but just switch it on and off a couple of times in a second

Utking said:
I think it's dead mate =/ but just switch it on and off a couple of times in a second
Click to expand...
Click to collapse
Couple of times in a second? I'm not a Flash man Or Shelden Cooper
Just tried but didn't work.

Short circuited battery? Hopefully it wasn't in the phone. Battery is dead, get Anker.

tinky1 said:
Short circuited battery? Hopefully it wasn't in the phone. Battery is dead, get Anker.
Click to expand...
Click to collapse
Already ordered stock battery. When Anker is available to Europe I will order it too.

Figure_desire said:
Already ordered stock battery. When Anker is available to Europe I will order it too.
Click to expand...
Click to collapse
Then buy the chichitek one, it's awesome and lasts just as long as the anker, if not longer, and they ship to europe! i got two chichitek batteries+ charger for 25$ usd inc shipping to norway

Battery issue. Help me?

I'm charging my tablet and I've noticed it never reaches full battery (100%). It hangs at 99% but then, if I unplug the cable, it shows 100%. 99% is shown again if I plug the cable back in. Also, when it's charging and the tablet is switched off, the bar never stops at full charge. The battery seems to run out faster too. Is there a way to recalibrate or to fix it? What has probably happened?
Sent from my GT-P3110 using XDA Premium HD app

Don't trust your battery display, its an liar. It cames strange, when your battery its discharging when its plugged in. So he must lie, to avoid massive failure message to the manufactures. I think with your battery its all ok.
You wake up, pulls the fully charged cell phone from the string and throws a quick glance in the e-mails. On the night was the smartphone loaded and the battery level indicator shows 100%. After a quick shower a customer wants to send an important file that you forgot the night before. Looking at the phone and determines that the battery is already down to 90%. A battery loss of 10% in 10 minutes? The phone must be broken!
A common criticism of today's smartphones is their short battery life compared to older phones. A few years ago it was quite possible that, after a week's holiday with still remaining battery life came back, if you forgot the charger (I do not happen more than once). In the newest phones on the market can however be lucky if you zurandekommt a weekend, without re-charging.
Basically, that's understandable. His time had phones a manageable list of functions: call and be called. Today one uses the device for e-mail, Web surfing, GPS navigation, photos, video games and a lot of other things. Earlier mobile phones had tiny displays, today they have gigantic screens with bright and vivid colors. All these features come at a price: a relatively high power consumption.
Interestingly, the underlying improvements in battery management problem of perception of the average user. Old cell phones put a pretty unelegantes charging behavior of the day: In general, you invited the battery up to the upper capacity limit and then switched to the mode "trickle charge" to ensure the highest level of battery charge. In this way they had in the short term always the best battery hurt, but the battery in the long run. The Battery University website that sets us apart precisely:
The period in which a battery at full charge should remain as short as possible, be kept. If high voltage will cause corrosion, especially at elevated temperatures.
And that is also the reason why "lose" many modern mobile phones up to 10% of their charge within a few minutes after they are sealed up from the charger. In truth, the batteries have been charged only for a brief moment to 100%. After that, the battery management has ensured that the unit discharges back to a level of about 90%. That the device was charged overnight, has no influence: The socket is only used to give a partial state of charge.
To investigate more closely, I Current widget installed on my HTC Droid Incredible. This app logs, is drawn as much electricity from the battery or the charger received. I have set the app so that it records every 10 seconds log data and data collected in this way a few days. Of course, depending on various factors (device hardware, firmware, kernel, etc), but the trends that I'm describing here to take on more and more mobile phones and are not limited to one device type or manufacturer.
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Click to collapse
Translate via Google

Xintorrim said:
I'm charging my tablet and I've noticed it never reaches full battery (100%). It hangs at 99% but then, if I unplug the cable, it shows 100%. 99% is shown again if I plug the cable back in. Also, when it's charging and the tablet is switched off, the bar never stops at full charge. The battery seems to run out faster too. Is there a way to recalibrate or to fix it? What has probably happened?
Sent from my GT-P3110 using XDA Premium HD app
Click to expand...
Click to collapse
I think your battery is all OK.
Modern batteries never load 100 %.

If you look at the battery charging current when state of charge is 99% ( for example with BMW app.) you will see that the charging current keeps at a higher level than 260mA.
This means that the ''leakage current'' of your battery is a little bit too high. This happen fairly frequently with Li-ion battery on all smarphones and tablets.
Do not warry, you will not loose any significant battery capacity if you stop the charging process at 99%.
You may see a typical current charging curve here: http://78michel.unblog.fr/samsung-galaxy-tab-2-10-1-tests/ ; the 100% limit was reached in this example.
I do not think that this ''high'' leakage current could be related to any battery failure.

Dummy Battery Problem

First of all, i have removed the battery from the tablet and i am supplying energy from the battery terminals (in this case, i want to be able to use my charging socket for the “OTG function”)
Even though giving the constant 4.2 volt electricity with this technic, battery gauge still drains from the tablet
im using chinese branded device as tablet by the way.Device is rooted with Android 10 go edition in it.
Normally, it has 2000mAh battery and the draining speed/principle is same as the above scenario
i’m waiting for the solution ideas or any suggestions

What exactly are you trying to accomplish?
Lithium ion batteries should NEVER be directly charged with a power source. Tablets and phones have charging controllers that regulate the charging current and voltage to avoid overcharging the battery, which at best reduces battery life, and at worst can cause catastrophic failure - including explosion and fire.

V0latyle said:
What exactly are you trying to accomplish?
Lithium ion batteries should NEVER be directly charged with a power source. Tablets and phones have charging controllers that regulate the charging current and voltage to avoid overcharging the battery, which at best reduces battery life, and at worst can cause catastrophic failure - including explosion and fire.
Click to expand...
Click to collapse
First of all, thank you for thinking of me. I am an experienced electronic engineer and have knowledge of Li-ion batteries. For the project that I am working on, I have to not use batteries due to the variation in ambient temperature.
Since I know that a fully charged battery provides 4.2 volts of energy, i remove the battery and so, supply this voltage from the place where the battery should normally be inserted.
When I turn on the tablet, the battery percentage shows 100%, after 20 minutes it drops to 85% approximately.
I don’t give the direct energy to the battery btw, on the contrary, i’m giving the energy from another source that the battery should normally give.
The attached photo can help you to have an idea for the situation
I just need to prevent the system for lowering the battery level as if like there is still battery in the tablet

brkedmrts said:
First of all, thank you for thinking of me. I am an experienced electronic engineer and have knowledge of Li-ion batteries. For the project that I am working on, I have to not use batteries due to the variation in ambient temperature.
Since I know that a fully charged battery provides 4.2 volts of energy, i remove the battery and so, supply this voltage from the place where the battery should normally be inserted.
When I turn on the tablet, the battery percentage shows 100%, after 20 minutes it drops to 85% approximately.
I don’t give the direct energy to the battery btw, on the contrary, i’m giving the energy from another source that the battery should normally give.
The attached photo can help you to have an idea for the situation
I just need to prevent the system for lowering the battery level as if like there is still battery in the tablet
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Oh okay, I suspected that's what you were doing, I was just trying to make sure in the interest of safety and all that. It's all fun and games until someone gets hurt...
It's really hard to say why the battery gauge reports 85% even though you're supplying 4.2 volts of power. Depending on the firmware, Android battery gauges aren't simple voltmeters that simply display a percentage based on a certain voltage curve. They're a bit more advanced than that, and factor in the load on the battery too.
Here is a better explanation on how the systems work.

I would like to add another question that makes me wonder, will the battery percentage stay constant somewhere and/or will it start to rise after some point?
If there is no way to prevent the battery from decreasing in terms of software, I don't want the screen to go black when it reaches 15% and turn off at 0%. I'm going to make a supercapacitor and a modification to charge.
Or if I arrange the android as if there is a battery near infinity, I think that I can almost stop the battery percentage decrease rate, is that logic possible?

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brkedmrts said:
I would like to add another question that makes me wonder, will the battery percentage stay constant somewhere and/or will it start to rise after some point?
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I honestly don't know.
brkedmrts said:
If there is no way to prevent the battery from decreasing in terms of software, I don't want the screen to go black when it reaches 15% and turn off at 0%. I'm going to make a supercapacitor and a modification to charge.
Or if I arrange the android as if there is a battery near infinity, I think that I can almost stop the battery percentage decrease rate, is that logic possible?
Click to expand...
Click to collapse
If you're powering the device via a constant DC supply that doesn't drop voltage under load, I would imagine the battery indicator would eventually stop at some point and just remain at a certain percentage. Again, this depends on what sort of controller the device has; if it's an adaptive learning battery management system, it might be ignoring the supply voltage, and is calculating how much power the device has used so far. Eventually it'll figure out that the voltage isn't dropping as expected, but I have absolutely no idea what it'll do.
I'd say just leave it playing video or something for a while and see what happens.

V0latyle said:
I honestly don't know.
If you're powering the device via a constant DC supply that doesn't drop voltage under load, I would imagine the battery indicator would eventually stop at some point and just remain at a certain percentage. Again, this depends on what sort of controller the device has; if it's an adaptive learning battery management system, it might be ignoring the supply voltage, and is calculating how much power the device has used so far. Eventually it'll figure out that the voltage isn't dropping as expected, but I have absolutely no idea what it'll do.
I'd say just leave it playing video or something for a while and see what happens.
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I had decided to try my super capacitor idea. However, For a device whose charge level drops while charging with its original battery installed, this was not very wise.
but I added a capacitor as shown in the attached image and I've been testing it for 25 minutes.
battery percentage 99% for last 20 minutes.I t hope I managed to manipulate it somehow.
I will be sharing the results,Also, thank you for your interest.

brkedmrts said:
I had decided to try my super capacitor idea. However, For a device whose charge level drops while charging with its original battery installed, this was not very wise.
but I added a capacitor as shown in the attached image and I've been testing it for 25 minutes.
battery percentage 99% for last 20 minutes.I t hope I managed to manipulate it somehow.
I will be sharing the results,Also, thank you for your interest.
Click to expand...
Click to collapse
Hey there, were you able to work it out?