[Windows Central Question]

So i took my battery out and connected it to a simple circuit and it was working normally. After i was finished with that i have put the battery back in the phone but my phone didn't show any signs of life. When i connect it to the charger it shows that the battery is empty and that it is charging.
The phone is Lumia 640.
Any help please?

[gpobernardo]

How were you able to determine that the battery worked "normally" when you connected it to that simple circuit? The battery may have discharged, but that doesn't necessarily mean that it discharged "normally" since the circuit is different from the circuit of your phone.

The battery has been used beyond what it was designed for and is most probably broken. You may need to acquire a new battery either by having it replaced in the service center or through a warranty claim (if it will still be honored).

[Mario Jozic]

well i know the battery is still working because when i connect it to the circuit again the circuit works just fine.

[Harrie-S]

well i know the battery is still working because when i connect it to the circuit again the circuit works just fine.

So what is then the problem?.
Just put it in your phone and charge it and it should be okay.
Or do I miss something?

[Mario Jozic]

I did charge it for like 30 minutes or so. And it shows the sign of charging and as soon as i plug the charging cable off it dies and won't start

[RumoredNow]

You may have borked the smart chip inside the battery and without the chip, your phone will not see the battery.

[Mario Jozic]

But it shows how the battery is charging and how it's empty

[RumoredNow]

Follow up: How many of the pins on the battery did you use in your circuit? Just two?

[Mario Jozic]

and i tested it with the voltmeter and it has 3.8 volts (which is normal)

[Harrie-S]

I did charge it for like 30 minutes or so. And it shows the sign of charging and as soon as i plug the charging cable off it dies and won't start

When you disconnected the charger what was the battery level on your phone?

Anyhow charge it longer. It may be totally discharged and in this case the charging takes longer.
And double check the battery is placed good in your phone (makes good contact) and the contact area's are clean.
And if after 2 hours still the same happens see the first answer on your initial question.

[Mario Jozic]

yes, just two, the + and the - . It is indicated on the battery which is which

[gpobernardo]

well i know the battery is still working because when i connect it to the circuit again the circuit works just fine.

Batteries will release energy in any circuit - having the circuit work doesn't mean that the battery is working as it should. Batteries in electronic devices are usually designed to output energy at a certain rate - going beyond that rate can damage the battery. It's possible that your circuit drew out energy at a higher rate than what the battery was designed for.

Nonetheless, try the advice of Harrie-S and attempt to charge the battery.

[Mario Jozic]

When i disconnect the charger the phone just dies, it won't turn on or even vibrate.

[Mario Jozic]

Well the circuit is a small led 3 smt resistors and a chip... i don't see how that can take more than 2.5 A which the battery output is made for

[RumoredNow]

yes, just two, the + and the - . It is indicated on the battery which is which

And the other pin(s) you did not use were the ones for the chip to keep the battery safe.

Best bet: get a new battery and keep that one labeled "for experiments."

[Mario Jozic]

the third one?
well fu** hahaha..
i will try to charge it and if it doesn't work i will have to buy a new one i guess, i just don't know where.. i looked through e-bay and i can't find the battery.. Do you maybe know any shop that ships internationally? I am from Croatia...

[Mario Jozic]

And yeah, when i take out the battery and just plug the charger it won't do anything.. so then i think it recognizes the battery?

[RumoredNow]

So then it is not broken?

Empirical evidence shows it no longer functions properly. Sorry. It is your evidence. The battery will no longer power the phone even though it will power your circuit and appear to take charge when inserted in the phone...

Does Lumia not always boot when plugged into a charger? Does your Lumia boot when plugged into the charger with "experimental" battery in the circuit? That would show only circuit complete and Lumia might be running off of AC current... If Lumia will not boot or stay on solely under battery, the battery is compromised. Ipso facto.

[Harrie-S]

And be aware if the security circuit is damaged you may overload the battery so keep an eye on it if it's charging in your phone.

Furthermore check which type of battery the 640 has. Maybe it's the same as another phones battery.

[Mario Jozic]

without battery, no it doesn't boot... it just shows charging and stays on it...

[RumoredNow]

without battery, no it doesn't boot... it just shows charging and stays on it...

Does it boot WITH the battery at all? Ever? Connected to AC or not?

I know it does not boot without a battery in to complete the circuit.

[Mario Jozic]

yes it boots but not to a point of where i can use the phone, just to the point of the charging animation

[RumoredNow]

Then it is not booting...

An (imperfect) analogy. You may get into the Bios or UEFI on a computer even if the OS will not boot. Something akin to that is going on. The fact of the charge indicator showing up just means that the circuit is completed and the display shows this fact. However, as is well known, when you plug a Lumia into the charger it boots up. Since yours will not boot to the OS your battery chip is fried.

I honestly don't know why this has to be argued and repeated so often and so much.

You killed your battery by experimenting with it. Please face that fact and move on.

[gpobernardo]

yes it boots but not to a point of where i can use the phone, just to the point of the charging animation

Have you tried going to a service center?

As in any forum, we can only do as much as give advice and recommendations as to what can be done about certain things. Unless we have Super Sight (as in Stan Lee's Super Humans) or some strong clairvoyant ability, it's fairly difficult to give an accurate diagnosis of a technical or hardware-level problem remotely. But those guys in the service center will be able to see, touch and disembowel your device to see what went wrong with it, what can be done with it and if fees will be charged or not on what they will be doing with it.

For that type of problem, we can only go as far as "we think this happened" based on "what you've said happened". We'd like to help - that's why we're here - but remote assistance could only go so far.

So, again, it's most likely that your battery has been damaged by using it for a purpose other than what it was intended for (using it in a different device other than the phone it came with). Try taking it to a service center and have your phone (or your battery more specifically) diagnosed and potentially replaced while keeping in mind the warranty (and the implied fees for the repair) of your device - be careful with what you tell them (it could mean the difference between paying and not paying).