R@ndom
Enlightened
Would a old mobile phone with some wire and magnets soldered into the batterie compartment work as a emergency charger?
Using mobile phone as li-ion charger?
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TranceAddict
Newly Enlightened
this is exactly what i am thinking to do, there are always 3 pins battery terminal at nokia phone, and supposedly one +, one -, and one signal/data to read the battery ID, if it doesn't match or unknown to the phone firmware charging will not begin.
what I am trying to do is to take out the protection PCB from phone battery and connect it to 18650, and finally connect the protection PCB to phone battery terminal.
please advice me
what I am trying to do is to take out the protection PCB from phone battery and connect it to 18650, and finally connect the protection PCB to phone battery terminal.
please advice me
I have already done that with success.
Read Using a cellular phone as a Li-Ion batteries charger Thread. When discharged to 3.8 volts the cellphone (an LG one) gives 500mA. When almost fully charger the battery gets 100mA from the cellphone.
I tried to do the same with other brand cellphones and it didn't work. I guess it is because some batteries has smart circuits inside and the cellphone asks the battery for information about current state before starting to charge. Since we are connecting just two of those three pins, the cellphone doesn't recognize the battery and doesn't start to charge it. One of my old Nokia cellphone didn't charge the battery.
Read Using a cellular phone as a Li-Ion batteries charger Thread. When discharged to 3.8 volts the cellphone (an LG one) gives 500mA. When almost fully charger the battery gets 100mA from the cellphone.
I tried to do the same with other brand cellphones and it didn't work. I guess it is because some batteries has smart circuits inside and the cellphone asks the battery for information about current state before starting to charge. Since we are connecting just two of those three pins, the cellphone doesn't recognize the battery and doesn't start to charge it. One of my old Nokia cellphone didn't charge the battery.
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TranceAddict
Newly Enlightened
did you try taking out the battery protection pcb and use it to connect across li-ion battery and battery terminal?
charger connection diagram for Nokia battery (BL-5C):
extra benefit as two protections PCB are cascade together.
BSI= Battery Size Indicator (typically a 47K resistor)
Someone please try I don't have discarded battery on hand at the moment.
charger connection diagram for Nokia battery (BL-5C):
extra benefit as two protections PCB are cascade together.
BSI= Battery Size Indicator (typically a 47K resistor)
Someone please try I don't have discarded battery on hand at the moment.
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No, I didn't. I preferred to live.
As far as I remember, the third pin at least in some of the Nokia batteries was a thermistor output. To make the phone work on the external battery I had to connect the appropriate resistor to it. It's quite possible that during the charge it would be also required.
TranceAddict
Newly Enlightened
expert advise needed. please comment
TranceAddict
Newly Enlightened
anyone has experience in this ? please share
TranceAddict
Newly Enlightened
well, finally built the charger using this design, on 18650 charge terminated just nicely at 4.2v, able to achieve 800ma charge rate by changing different resistance of the battery size indicator (79Kohm).
although it may look like a poor man charger but it has lot of safety measures (accurate charge termination by mobile + nokia battery pcb cut-off + AW pcb cut off) as long as you don't short circuit and route the wire properly
although it may look like a poor man charger but it has lot of safety measures (accurate charge termination by mobile + nokia battery pcb cut-off + AW pcb cut off) as long as you don't short circuit and route the wire properly
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