# By knowing the charge capacity, can one find how many hours minutes , my phone charged to 100% from

#### jraju

Joined Jul 23, 2017
67
Hi, i am having samsung galaxy j2 pro, having battery capacity of 2600 mah. I am having samsung charger.can i know , how much hours it will take to charge full from zero.
what are the other input, we need
please also tell the formula.I heard that even when the adaptor or charger capacity is more, it is the phone unit charger, that will decide how mcuh current has to be taken from the plug current. Is it correct
Is the charger inbuilt different from battery in the device

#### dl324

Joined Mar 30, 2015
13,141
There are too many variables.
1. Battery condition
2. Current available from charger
3. Other activity on the phone
4. WiFi and/or Bluetooth enabled
Install a battery monitoring app. Over time, it will adapt to your battery and estimate charge time. At least it'll try. Mine isn't accurate.

#### wayneh

Joined Sep 9, 2010
17,153
what are the other input, we need
Charging of the phone battery is controlled by the phone itself. The phone uses a set of algorithms programmed by the manufacturer to optimize the process as best they know how, while balancing competing factors of fast charging against battery life and so on. The manufacturer might share that with the public, but I doubt it. So there is a "formula", but I doubt you can get it. You're left with performing the experiment yourself.

#### jraju

Joined Jul 23, 2017
67
Ceteriparibus, other things being equal, i ask this query.
I also ask this query in this forum, so that experts in the field may give me the idea.
DL: has said current available from charger.
You get normal current and the charger is from manufacturer.
I also ask, if the inbuilt charger is any different from the battery inside the phone.
Assume, that phone is being charger in the device off position.
There should be a formula, for a healthy battery and charger.
How come than this my battery capacity is 2600 mah.
it denotes, 2600 million amps per hour is it not
expecting further replies

#### wayneh

Joined Sep 9, 2010
17,153
it denotes, 2600 million amps per hour is it not
milliamp-hours are a measure of charge, in current in 0.001A (1mA) times hours. Current in amps is units of charge (in coulombs) per second.

Assume, that phone is being charger in the device off position.
There should be a formula, for a healthy battery and charger.
Did you not believe me? Yes there's a formula - that your phone uses whether it's on or off - but customers are usually not entitled to it. If you know the chemistry of your battery, you can read at Battery University how best to charge that chemistry. But there's nothing you can do with that knowledge to change the charger and phone.

#### kubeek

Joined Sep 20, 2005
5,758
Is an answer "that depends" adequate? Every phone is different, has different battery and the managment has different views on how many cycles a battery should last, which has direct impact on the upper and lower levels of voltage that the phone allows, and the charging current.
You can charge a typical phone li-ion battery under an hour, but how long will it last? Maybe 300 cycles? Or you can charge it slow say three hours, and it might last 2000 cycles.
The way the chemistry works allows you to change how much capacity the battery stores, based on what is the finish voltage level when charging. Higher voltage, higher stored capacity. But significantly shortened lifetime. Some OS updates even lowered this limit because the batteries could catch fire or be unusable too soon.

So to make it short, my idea of normally fuilly charging a phone is between 1-3hours. Anything shorter and the battery likely has very little capacity, anything longer and the charger is probably inadequate.

#### jraju

Joined Jul 23, 2017
67
Hi, thanks for all the answers. But ,if a formula is there, what is the secret behind it. By knowing the battery chemistry , what is harm in it.
the battery would last for some 3 years ,at the maximum, then start spinning alerting to replace with new.
i am having a different view that every body is entitled to know the secrets if it all is there
for eg. recently, i had slow charging problem and went to the service centre. they checked and asked me to replace the battery .i did.
then also problem persisted . then after inspection asked me to replace the board, as there is no problem in charger or usb cable.
i only had one charger, so decided to test . i changed the plug point, nope. Then i thought of buying a genuine charger and bought it.
then i checked for app if any to test. there was one full charge alarm among many apps i tried.
I used the new usb cable (of th)e new charger) and tested . previously, it was 4 1/2 to 5hours of charging, now came down to 2 hours 54 minutes. then i checked with the app, the app when plugged showed the maximum time my battery could charge. Had i used the app,by only changing the usb cable, i need not have bought the charger .
So here comes the idea of knowing the formula, of how much hours each battery would charge, ceteriparibus.
i do not think that there is any secrecy, but the formula evades us.

#### jraju

Joined Jul 23, 2017
67
i am also surprised how it charges, if the cable is defective.normally it would not charge had there been a cut in the usb cable internal wires. i escaped from changing the mother board , at half cost of the phone i bought . what would be the cuase experts

#### spinnaker

Joined Oct 29, 2009
7,835
There are too many variables.
1. Battery condition
2. Current available from charger
3. Other activity on the phone
4. WiFi and/or Bluetooth enabled
Install a battery monitoring app. Over time, it will adapt to your battery and estimate charge time. At least it'll try. Mine isn't accurate.
5. Resistance of USB cable assuming it is connected by USB cable.

Wireless chargers throw in a bunch of variables too.

#### kubeek

Joined Sep 20, 2005
5,758
Bad cable, from the point of view of the phone, is equivalent to bad charger. The phone as far as I know has two variables by which it controls how much power it can get. First is the resistor combination on the D+ and D- pins of the usb, that usually says how much power it is allowed to draw. That could say anywhere from 0.5A to 2A or more on standard USB. USB-C and high power modes are even more complicated and involve digital negotiation of the max power. However, if those numbers say the phone can draw 10A from the plug, and at 1A the voltage starts dropping, many phones will notice that and keep the charging current below that to achieve as fast charging as possible. And the voltage can drop either due to a bad thing cable, or due to inadequate charger that claims more than it can do. Anyway, the fallback is usually the standard usb 0.5A at 5V, therefore 2.5W. 2200mAh battery at 3.8V average will take 8.36Wh of energy to charge, therefore about 3.3 hours with 0.5A and 5V supply and 100% efficiency.

#### spinnaker

Joined Oct 29, 2009
7,835
There is the quality of the cable too. I have had some cheap USB cables that simply suck at charging .

#### jraju

Joined Jul 23, 2017
67
On surfing the web , after i wrote my answers, i have a feeling that i have to include amerage capacity of the charger. i would like the experts to provide me a clue. it says, capacity/amperage and in some forum, it says, capacity,efficiency and amperage. i enclose the picture of both charges, as i do not know the amperage. capacity of li on battery 2600 mah or 2-6 ah.
the left most picture new charger, the other is the old charger with the phone
i also want to know, the inbuilt charger is our battery or some other thing. where it is located in phone. can we see

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#### kubeek

Joined Sep 20, 2005
5,758
If that first one is actual genuine samsung and not some chinese/indian knockoff (that will kill you in your sleep) than that is the one that should be the fastest. But you still need the proper cable, the cheap ones have so little copper that you burn most of the power in the cable and not spend it charging your phone.

#### wayneh

Joined Sep 9, 2010
17,153

#### jraju

Joined Jul 23, 2017
67
All the above answers are very general. i want to know the formula if it could find the maximum hours a battery strength charges from zero to 100%.
Will the device get the same voltage from the plug
if i know the voltage, and amperage cannot i know the maximum hours
the batteries above are genuine samsung chargers.
one came with the phone pack and the other the latest bought.

#### dl324

Joined Mar 30, 2015
13,141
i want to know the formula if it could find the maximum hours a battery strength charges from zero to 100%.
There is no formula because the batteries in phones don't charge at a constant current. They'll typically start with a fast charge, then taper. Then they monitor battery voltage for a negative delta voltage (NDV) of around 5 mV to trigger end of charge.

A smart smartphone would stop charging when the battery was charged. Dumb ones would continue baking the battery.

I have a battery monitoring app on my phone and tablet. It accuses me of overcharging my battery if I let it continue charging after it's at 100%. I haven't checked another app that monitors battery current to see if it actually keeps charging.

#### wayneh

Joined Sep 9, 2010
17,153
This is my last attempt!

All the above answers are very general. i want to know the formula
Too bad. Samsung doesn't want to share that with you. It doesn't matter how many times you ask.
Will the device get the same voltage from the plug
No, that charger appears to support "adaptive" fast charging and can jump to the higher voltage for devices that accept that. I have no idea if it can be at a voltage in between but if you read up on Samsung charging technology it may disclose this. You could look up whether your phone is such a device. If it is not, the voltage will stay constant at 5V. The current drawn will be dictated by the programming of the phone.
if i know the voltage, and amperage cannot i know the maximum hours
Yes, but the amperage will not be constant. The phone will control it. You could measure it, but it might vary from time to time.

#### wayneh

Joined Sep 9, 2010
17,153
one came with the phone pack and the other the latest bought.
I should mention that if the charger didn't come directly from Samsung, it's probably counterfeit. Amazon is awash in counterfeit Apple and Samsung chargers. It's impossible to tell when you order and it's even extremely difficult to tell once you have one, except for the lousy performance. The counterfeits are very convincing in appearance.

#### jraju

Joined Jul 23, 2017
67
Hi wayenh and dl
valuable information.
hi, wayneh,

assuming amperage is constant, what is the formula. i noticed that full charge alarm gives me the percent of battery capacity at diffeent level of charging. i noticed one or two.
at one time it shows 10% when the mah is 260
and at 74%, as enclosed
Hi, dl324, please tell me the name of app

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#### dl324

Joined Mar 30, 2015
13,141
I use Battery Doctor to track charging (and discharging) and Ampere to monitor battery stats (current, voltage, temperature).