Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a whole heap of button pressing etc to reset/ get it going and nothing worked so concluded the charging circuit is fried. I am now trying to get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the terminals are labelled +, blank, -, blank - blank = no label. The battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the phone (e.g. I could solder wires onto the pins in the phone and somehow get 3.85v from AA batteries or maybe charge an old mobile battery and connect it in) or charge the battery e.g. using a AA battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.

On 30/12/2020 12:05, wrote:

Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a whole heap of button pressing etc to reset/ get it going and nothing worked so concluded the charging circuit is fried. I am now trying to get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the terminals are labelled +, blank, -, blank - blank = no label. The battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the phone (e.g. I could solder wires onto the pins in the phone and somehow get 3.85v from AA batteries or maybe charge an old mobile battery and connect it in) or charge the battery e.g. using a AA battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.


I have a load of these ....quite good lcd display

https://www.ebay.co.uk/itm/Universal...Cclp%3A2334524

On 30/12/2020 12:14, Jim GM4DHJ ... wrote:

On 30/12/2020 12:05, wrote:

Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge.Â* I tried
a whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried.Â* I am now trying to
get all the old photos off it and am after some cunning ideas from the
group

The battery is removable and has 4 connectors on it - on the battery
the terminals are labelled +, blank, -, blank - blank = no label.Â* The
battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the
phone (e.g. I could solder wires onto the pins in the phone and
somehow get 3.85v from AA batteries or maybe charge an old mobile
battery and connect it in) or charge the battery e.g. using a AA
battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.


I have a load of these ....quite good lcd display

https://www.ebay.co.uk/itm/Universal...Cclp%3A2334524


sorry I thought you just wanted an external charger.....

On Wednesday, 30 December 2020 at 12:16:01 UTC, Jim GM4DHJ ... wrote:
On 30/12/2020 12:14, Jim GM4DHJ ... wrote:
On 30/12/2020 12:05, wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried
a whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried. I am now trying to
get all the old photos off it and am after some cunning ideas from the
group

The battery is removable and has 4 connectors on it - on the battery
the terminals are labelled +, blank, -, blank - blank = no label. The
battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the
phone (e.g. I could solder wires onto the pins in the phone and
somehow get 3.85v from AA batteries or maybe charge an old mobile
battery and connect it in) or charge the battery e.g. using a AA
battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.

I have a load of these ....quite good lcd display

https://www.ebay.co.uk/itm/Universal...Cclp%3A2334524

sorry I thought you just wanted an external charger.....

Thanks - yeah saw these. Was hoping to improvise something so I could get it running for a couple of hours.

On 30/12/2020 12:05, wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a whole heap of button pressing etc to reset/ get it going and nothing worked so concluded the charging circuit is fried. I am now trying to get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the terminals are labelled +, blank, -, blank - blank = no label. The battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the phone (e.g. I could solder wires onto the pins in the phone and somehow get 3.85v from AA batteries or maybe charge an old mobile battery and connect it in) or charge the battery e.g. using a AA battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.

Have you got any of these: an accurate voltmeter, a multimeter, a
variable power supply?

Bill

On Wednesday, 30 December 2020 at 14:43:44 UTC, wrote:
On 30/12/2020 12:05, wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a whole heap of button pressing etc to reset/ get it going and nothing worked so concluded the charging circuit is fried. I am now trying to get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the terminals are labelled +, blank, -, blank - blank = no label. The battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the phone (e.g. I could solder wires onto the pins in the phone and somehow get 3.85v from AA batteries or maybe charge an old mobile battery and connect it in) or charge the battery e.g. using a AA battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.

Have you got any of these: an accurate voltmeter, a multimeter, a
variable power supply?

Bill
I have a multimeter

On 30/12/2020 14:47, wrote:
On Wednesday, 30 December 2020 at 14:43:44 UTC, wrote:
On 30/12/2020 12:05, wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a whole heap of button pressing etc to reset/ get it going and nothing worked so concluded the charging circuit is fried. I am now trying to get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the terminals are labelled +, blank, -, blank - blank = no label. The battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the phone (e.g. I could solder wires onto the pins in the phone and somehow get 3.85v from AA batteries or maybe charge an old mobile battery and connect it in) or charge the battery e.g. using a AA battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.

Have you got any of these: an accurate voltmeter, a multimeter, a
variable power supply?

Bill
I have a multimeter

At the risk of stating the bleeding obvious, does it power up when
connected to a power supply? Firstly with the battery in place, then
with the battery removed. I would be pretty confident that the board is
protected from being fried by a 5 volt USB supply with the battery removed.

As you probably realise, the risk in messing around with the battery is
that you overcharge it and it catches fire. In principle you should be
relatively safe by feeding appropriate volts direct to the phone pins,
but as Bill says it's safer to do that with a good quality variable
voltage power supply and a meter where you are confident about at least
the first decimal place.

On 30/12/2020 12:05, wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a whole heap of button pressing etc to reset/ get it going and nothing worked so concluded the charging circuit is fried. I am now trying to get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the terminals are labelled +, blank, -, blank - blank = no label. The battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the phone (e.g. I could solder wires onto the pins in the phone and somehow get 3.85v from AA batteries or maybe charge an old mobile battery and connect it in) or charge the battery e.g. using a AA battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.

get a single cell lithium or charge up the one you have

Actually its 3.7v medium 4.2v full and IIRC about 3.3 flat



--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

At the risk of stating the bleeding obvious, does it power up when
connected to a power supply? Firstly with the battery in place, then
with the battery removed. I would be pretty confident that the board is
protected from being fried by a 5 volt USB supply with the battery removed.


Yes tried both and nothing. After posting this I thought I would check to see if the battery voltage increases with it in the phone on charge. It was reading 0v (or 0.3 on the 300mV setting - not sure what that means) and now after a couple of hours it is reading 0.2v (the 300mV setting is saying "overload"). So it seems like it might be charging albeit very slowly. Will leave it plugged in to see if it holds any charge.

As you probably realise, the risk in messing around with the battery is
that you overcharge it and it catches fire. In principle you should be
relatively safe by feeding appropriate volts direct to the phone pins,
but as Bill says it's safer to do that with a good quality variable
voltage power supply and a meter where you are confident about at least
the first decimal place.

Yes my multimeter is an old Fluke digital one so should be accurate. How best do I generate the voltage required?

On Wednesday, 30 December 2020 at 15:13:30 UTC, wrote:
At the risk of stating the bleeding obvious, does it power up when
connected to a power supply? Firstly with the battery in place, then
with the battery removed. I would be pretty confident that the board is
protected from being fried by a 5 volt USB supply with the battery removed.

Yes tried both and nothing. After posting this I thought I would check to see if the battery voltage increases with it in the phone on charge. It was reading 0v (or 0.3 on the 300mV setting - not sure what that means) and now after a couple of hours it is reading 0.2v (the 300mV setting is saying "overload"). So it seems like it might be charging albeit very slowly. Will leave it plugged in to see if it holds any charge.
As you probably realise, the risk in messing around with the battery is
that you overcharge it and it catches fire. In principle you should be
relatively safe by feeding appropriate volts direct to the phone pins,
but as Bill says it's safer to do that with a good quality variable
voltage power supply and a meter where you are confident about at least
the first decimal place.
Yes my multimeter is an old Fluke digital one so should be accurate. How best do I generate the voltage required?

Have you checked the charger? When this happened to me it was the charger that was knackered. It is unusual for a phone not to power up with a charger connected this has been the case going back years I believe. The only Samsung phone I owned was a Galaxy Ace and you could power from the charger and do all even though the battery was pancaked.

Richard

On Wednesday, 30 December 2020 at 15:06:26 UTC, The Natural Philosopher wrote:
On 30/12/2020 12:05, wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a whole heap of button pressing etc to reset/ get it going and nothing worked so concluded the charging circuit is fried. I am now trying to get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the terminals are labelled +, blank, -, blank - blank = no label. The battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the phone (e.g. I could solder wires onto the pins in the phone and somehow get 3.85v from AA batteries or maybe charge an old mobile battery and connect it in) or charge the battery e.g. using a AA battery charger/ car battery charger/ old mobile?

Anyone have any ideas?

thanks

Lee.

get a single cell lithium or charge up the one you have

Actually its 3.7v medium 4.2v full and IIRC about 3.3 flat



--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

I could charge the one I have but not sure how to do that without the phone being able to do it?

wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a
whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried. I am now trying to
get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the
terminals are labelled +, blank, -, blank - blank = no label. The
battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the
phone (e.g. I could solder wires onto the pins in the phone and somehow
get 3.85v from AA batteries or maybe charge an old mobile battery and
connect it in) or charge the battery e.g. using a AA battery charger/ car
battery charger/ old mobile?

Anyone have any ideas?

thanks


Dont mean to be rude but have you tried another charger and a new usb
cable? Cables fail frequently, chargers less often but still do die
occasionally.

When youve tried a new/different charger/cable combination will the phone
power up when attached to the charger (with or without the battery
installed)?

If none of that works then I guess trying to charge the existing battery
out of the phone is worth a shot. Im pretty sure all Li-ion phone
batteries have built-in overcharge protection so I dont think the
explosion risk is high. ;-)

Tim

--
Please don't feed the trolls

In article ,
wrote:
My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a
whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried. I am now trying to
get all the old photos off it and am after some cunning ideas from the
group

Have you tried simply plugging it into a PC via a USB port, using a
suitable lead? The charger one may be power only.

You might find it sees the storage drive. That works with my S4.

--
*No radio - Already stolen.

Dave Plowman London SW
To e-mail, change noise into sound.

wrote:
Yes my multimeter is an old Fluke digital one so should be accurate. How
best do I generate the voltage required?

What do you have?

For a crude charger, a 5V supply with a silicon diode in series will make
4.3V. That's a bit high, so add another diode to make 3.6V. If the phone
charging circuit is merely complaining that the battery is dead flat,
bringing it up to 3.6V should be enough for the phone to take over. 3.6v is
not going to harm a functional battery.

Now we need to limit the current to prevent it charging too fast. Let's say
we'll limit the peak current to 200mA when it's dead flat (V across it is
0V, so we need to drop 3.6V). V=IR so V/I=R so 3.6/0.2 = 18 ohms. So if
you put an 18 ohm resistor in series you'll impose that 200mA limit. As the
cell voltage rises the current will tail off - it'll charge slowly but
safely this way.

So put diode-diode-18ohms in series across a 5V supply - you should see
maximum 3.6V across the resistor. Due to the current limit, it's safe to
keep it like this (assuming your resistor is at least 0.75W).

Now put the battery in series with this circuit and observe the voltage
across it. If you see the voltage rising slowly, that's good. If it rises
to 3.6v rapidly, the battery is knackered. If it stays at 0v it's shorted
(knackered, and really you shouldn't leave it for a long period to prevent
it cooking).

A 'proper' charger is constant-current/constant-voltage, so it does CC mode
for bulk charging and CV mode at the top of charge. The diode+resistor is a
very crude and slow approximation, but if the current is low enough it'll be
safe.

Theo

On 30/12/2020 15:55, Dave Plowman (News) wrote:
In article ,
wrote:
My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a
whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried. I am now trying to
get all the old photos off it and am after some cunning ideas from the
group

Have you tried simply plugging it into a PC via a USB port, using a
suitable lead? The charger one may be power only.

You might find it sees the storage drive. That works with my S4.

The photos might even be on a removable memory card.

--
Max Demian

On 30/12/2020 15:48, Tim+ wrote:
wrote:
Hi All,

My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a
whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried. I am now trying to
get all the old photos off it and am after some cunning ideas from the group

The battery is removable and has 4 connectors on it - on the battery the
terminals are labelled +, blank, -, blank - blank = no label. The
battery is apparently 3.85v Li-ion with a charge voltage of 4.4v/ 3.85v

So.... It there a way of either using a different source to power the
phone (e.g. I could solder wires onto the pins in the phone and somehow
get 3.85v from AA batteries or maybe charge an old mobile battery and
connect it in) or charge the battery e.g. using a AA battery charger/ car
battery charger/ old mobile?

Anyone have any ideas?

thanks


Dont mean to be rude but have you tried another charger and a new usb
cable? Cables fail frequently, chargers less often but still do die
occasionally.

When youve tried a new/different charger/cable combination will the phone
power up when attached to the charger (with or without the battery
installed)?


Agreed, it may also be a dodgy socket in the phone. You sometimes find
they will work with some cables but not with others.

On 30/12/2020 18:39, Max Demian wrote:
On 30/12/2020 15:55, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* wrote:
My wife's old Samsung Galaxy S5 died - it refuses to charge.Â* I tried a
whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried.Â* I am now trying to
get all the old photos off it and am after some cunning ideas from the
group

Have you tried simply plugging it into a PC via a USB port, using a
suitable lead? The charger one may be power only.

You might find it sees the storage drive. That works with my S4.

The photos might even be on a removable memory card.

Surely the OP would have thought of that, but perhaps I should me a
backup of the photos on my and swmbo's phones as the phones do not have
have slots for memory cards.

--
Michael Chare

On Wednesday, 30 December 2020 at 23:54:04 UTC, Michael Chare wrote:
On 30/12/2020 18:39, Max Demian wrote:
On 30/12/2020 15:55, Dave Plowman (News) wrote:
In article ,
wrote:
My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a
whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried. I am now trying to
get all the old photos off it and am after some cunning ideas from the
group

Have you tried simply plugging it into a PC via a USB port, using a
suitable lead? The charger one may be power only.

You might find it sees the storage drive. That works with my S4.

The photos might even be on a removable memory card.

Surely the OP would have thought of that, but perhaps I should me a
backup of the photos on my and swmbo's phones as the phones do not have
have slots for memory cards.

--
Michael Chare

Hi All,

Definitely a bit of an odd one this. The phone died last March (ish) with the symptom of not charging - left on for a few hours, no charging led and phone wouldn't turn on. Tried various chargers, leads, connecting it to a couple of PCs etc. nothing. Looking online there were a number of reset type fixes involving holding various button combinations, starting it with/ without battery etc. and no sign of life.

It was my wife's phone so she has been using an old iPhone 5 since which she hates. So... for Christmas I bought her a new Andorid phone. Yesterday I tried to get the photos off the old phone to put on the new one. No charging again so posted the above. After a couple of hours the charge in the phone went up very marginally but decided to leave it plugged in. All of a sudden, it seemed to suddenly charge (measured on MM to around 2v) and the led "I'm charging" lit up! Phone continued to charge as normal and now seems to work fine.

After all this there were only 2 (not interesting) photos which had not been copied to the server!.... I use an Android app which automatically copies all photos to my server via NFS for backup - it had been playing up resulting in you having to manually hit the upload button instead of doing it automatically. So given my wife rarely does it manually assumed there would be loads to do. Guess I should have tried to correlate the time stamps on the server with roughly when the phone died!

Anyway net result is she has a nice new phone and we have a spare if needed!

Anyone have any idea what suddenly spurred it into life? It was almost like it knew there was a new phone on the block Only thing I can thing of is that it has been in the cold utility room for the past few months - maybe this did something to the battery - like the "put it in the freezer" trick?

Thanks for all you help

Lee.

On 30/12/2020 12:22, wrote:
Thanks - yeah saw these. Was hoping to improvise something so I
could get it running for a couple of hours.

Simplest way might be to find someone else with a similar S5 phone and
charge it in that (or buy a new battery for it and hope it comes with
enough charge to do what you want). eg

https://www.duracelldirect.co.uk/pho...y-charger.html

You are unlikely to bodge something up that will fool the self
protection mechanism inside the battery and might well brick it.
(or worse start a lithium fire)

--
Regards,
Martin Brown

On 31/12/2020 11:14, wrote:
Anyone have any idea what suddenly spurred it into life? It was
almost like it knew there was a new phone on the block Only thing
I can thing of is that it has been in the cold utility room for the
past few months - maybe this did something to the battery - like the
"put it in the freezer" trick?

I may have insight. I once flattened some LIPO flight batteries badly.
(left em plugged in to a model for a week) The charge only recognised a
three cell battery as one cell and refused to charge it over 4v.

Loathe to condemn the battery without at least a try to restore it I
popped it on a nickel cell charger at low current - 100mA I think for a
few minutes. Once it read over 8V I put it on the proper charger.

It did charge, but the capacity and internal resistance were pants.

So it was ****ed, but it did hold a bit of charge

To get a battery replaced in a phone is about £40 including labour and
many little hole in the wall arcade shops will do it. I would get that
phone a new battery. Chances are it will spring to life.




--
The theory of Communism may be summed up in one sentence: Abolish all
private property.

Karl Marx

wrote:

Hi All,

Definitely a bit of an odd one this. The phone died last March (ish) with the symptom of not charging - left on for a few hours, no charging led and phone wouldn't turn on. Tried various chargers, leads, connecting it to a couple of PCs etc. nothing. Looking online there were a number of reset type fixes involving holding various button combinations, starting it with/ without battery etc. and no sign of life.

It was my wife's phone so she has been using an old iPhone 5 since which she hates. So... for Christmas I bought her a new Andorid phone. Yesterday I tried to get the photos off the old phone to put on the new one. No charging again so posted the above. After a couple of hours the charge in the phone went up very marginally but decided to leave it plugged in. All of a sudden, it seemed to suddenly charge (measured on MM to around 2v) and the led "I'm charging" lit up! Phone continued to charge as normal and now seems to work fine.

After all this there were only 2 (not interesting) photos which had not been copied to the server!.... I use an Android app which automatically copies all photos to my server via NFS for backup - it had been playing up resulting in you having to manually hit the upload button instead of doing it automatically. So given my wife rarely does it manually assumed there would be loads to do. Guess I should have tried to correlate the time stamps on the server with roughly when the phone died!

Anyway net result is she has a nice new phone and we have a spare if needed!

Anyone have any idea what suddenly spurred it into life? It was almost like it knew there was a new phone on the block Only thing I can thing of is that it has been in the cold utility room for the past few months - maybe this did something to the battery - like the "put it in the freezer" trick?

Thanks for all you help

Lee.

Lithium (all chemistries, like Cobalt or Iron Phosphate)
apparently do not have good charge acceptance at 0C or lower.

Not all charging chips are pro-active about this.
But this is some copied text from one chip that does care.

TEMP(Pin 1) :Temperature Sense Input Connecting TEMP pin to NTC thermistors output in
Lithium ion battery pack. If TEMP pins voltage is below 45% or above 80% of supply voltage VIN
for more than 0.15S, this means that batterys temperature is too high or too low, charging is
suspended. The temperature sense function can be disabled by grounding the TEMP pin.

Warming a Lithium pack up to room temperature before
charging, is a good practice for them.

Paul

On Thursday, 31 December 2020 at 13:24:45 UTC, Paul wrote:
wrote:

Hi All,

Definitely a bit of an odd one this. The phone died last March (ish) with the symptom of not charging - left on for a few hours, no charging led and phone wouldn't turn on. Tried various chargers, leads, connecting it to a couple of PCs etc. nothing. Looking online there were a number of reset type fixes involving holding various button combinations, starting it with/ without battery etc. and no sign of life.

It was my wife's phone so she has been using an old iPhone 5 since which she hates. So... for Christmas I bought her a new Andorid phone. Yesterday I tried to get the photos off the old phone to put on the new one. No charging again so posted the above. After a couple of hours the charge in the phone went up very marginally but decided to leave it plugged in. All of a sudden, it seemed to suddenly charge (measured on MM to around 2v) and the led "I'm charging" lit up! Phone continued to charge as normal and now seems to work fine.

After all this there were only 2 (not interesting) photos which had not been copied to the server!.... I use an Android app which automatically copies all photos to my server via NFS for backup - it had been playing up resulting in you having to manually hit the upload button instead of doing it automatically. So given my wife rarely does it manually assumed there would be loads to do. Guess I should have tried to correlate the time stamps on the server with roughly when the phone died!

Anyway net result is she has a nice new phone and we have a spare if needed!

Anyone have any idea what suddenly spurred it into life? It was almost like it knew there was a new phone on the block Only thing I can thing of is that it has been in the cold utility room for the past few months - maybe this did something to the battery - like the "put it in the freezer" trick?

Thanks for all you help

Lee.
Lithium (all chemistries, like Cobalt or Iron Phosphate)
apparently do not have good charge acceptance at 0C or lower.

Not all charging chips are pro-active about this.
But this is some copied text from one chip that does care.

TEMP(Pin 1) :Temperature Sense Input Connecting TEMP pin to NTC thermistors output in
Lithium ion battery pack. If TEMP pins voltage is below 45% or above 80% of supply voltage VIN
for more than 0.15S, this means that batterys temperature is too high or too low, charging is
suspended. The temperature sense function can be disabled by grounding the TEMP pin.

Warming a Lithium pack up to room temperature before
charging, is a good practice for them.

Paul

Ah interesting... I wonder if when I was taking the voltage of the battery I inadvertently grounded the temp pin then. The battery pads are about the same width as my probes so very likely I inadvertently shorted some of the pads

On 30/12/2020 16:36, Theo wrote:
wrote:
Yes my multimeter is an old Fluke digital one so should be accurate. How
best do I generate the voltage required?

What do you have?

For a crude charger, a 5V supply with a silicon diode in series will make
4.3V. That's a bit high, so add another diode to make 3.6V. If the phone
charging circuit is merely complaining that the battery is dead flat,
bringing it up to 3.6V should be enough for the phone to take over. 3.6v is
not going to harm a functional battery.

Now we need to limit the current to prevent it charging too fast. Let's say
we'll limit the peak current to 200mA when it's dead flat (V across it is
0V, so we need to drop 3.6V). V=IR so V/I=R so 3.6/0.2 = 18 ohms. So if
you put an 18 ohm resistor in series you'll impose that 200mA limit. As the
cell voltage rises the current will tail off - it'll charge slowly but
safely this way.

So put diode-diode-18ohms in series across a 5V supply - you should see
maximum 3.6V across the resistor. Due to the current limit, it's safe to
keep it like this (assuming your resistor is at least 0.75W).

Now put the battery in series with this circuit and observe the voltage
across it. If you see the voltage rising slowly, that's good. If it rises
to 3.6v rapidly, the battery is knackered. If it stays at 0v it's shorted
(knackered, and really you shouldn't leave it for a long period to prevent
it cooking).

A 'proper' charger is constant-current/constant-voltage, so it does CC mode
for bulk charging and CV mode at the top of charge. The diode+resistor is a
very crude and slow approximation, but if the current is low enough it'll be
safe.

Could he simply use a torch bulb as a current limiter?

Bill

On 30/12/2020 15:55, Dave Plowman (News) wrote:


You might find it sees the storage drive. That works with my S4.


Some phones ask you to OK the data link. If you did that you could
simply download the pics onto a PC.

Bill

More likely I think is a dodgy connection somewhere which will probably go
again just when it has lulled you into believing its OK.
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
" wrote in message
...
On Wednesday, 30 December 2020 at 23:54:04 UTC, Michael Chare wrote:
On 30/12/2020 18:39, Max Demian wrote:
On 30/12/2020 15:55, Dave Plowman (News) wrote:
In article ,
wrote:
My wife's old Samsung Galaxy S5 died - it refuses to charge. I tried a
whole heap of button pressing etc to reset/ get it going and nothing
worked so concluded the charging circuit is fried. I am now trying to
get all the old photos off it and am after some cunning ideas from the
group

Have you tried simply plugging it into a PC via a USB port, using a
suitable lead? The charger one may be power only.

You might find it sees the storage drive. That works with my S4.

The photos might even be on a removable memory card.

Surely the OP would have thought of that, but perhaps I should me a
backup of the photos on my and swmbo's phones as the phones do not have
have slots for memory cards.

--
Michael Chare

Hi All,

Definitely a bit of an odd one this. The phone died last March (ish) with
the symptom of not charging - left on for a few hours, no charging led and
phone wouldn't turn on. Tried various chargers, leads, connecting it to a
couple of PCs etc. nothing. Looking online there were a number of reset type
fixes involving holding various button combinations, starting it with/
without battery etc. and no sign of life.

It was my wife's phone so she has been using an old iPhone 5 since which she
hates. So... for Christmas I bought her a new Andorid phone. Yesterday I
tried to get the photos off the old phone to put on the new one. No charging
again so posted the above. After a couple of hours the charge in the phone
went up very marginally but decided to leave it plugged in. All of a
sudden, it seemed to suddenly charge (measured on MM to around 2v) and the
led "I'm charging" lit up! Phone continued to charge as normal and now
seems to work fine.

After all this there were only 2 (not interesting) photos which had not been
copied to the server!.... I use an Android app which automatically copies
all photos to my server via NFS for backup - it had been playing up
resulting in you having to manually hit the upload button instead of doing
it automatically. So given my wife rarely does it manually assumed there
would be loads to do. Guess I should have tried to correlate the time
stamps on the server with roughly when the phone died!

Anyway net result is she has a nice new phone and we have a spare if needed!

Anyone have any idea what suddenly spurred it into life? It was almost like
it knew there was a new phone on the block Only thing I can thing of is
that it has been in the cold utility room for the past few months - maybe
this did something to the battery - like the "put it in the freezer" trick?

Thanks for all you help

Lee.

williamwright wrote:
Could he simply use a torch bulb as a current limiter?

I don't know the resistance curve of a torch bulb, but I'd want to make sure
I never put more than 4.2V across the lithium cell. If the cell isn't
taking much charge current I'd expect the cell voltage to rise above 4.2V
which is likely to damage the cell (not in a fireworks kind of way if the
current is low, but in terms of reduced cycle life). The torch bulb also
won't back off the current as it reaches top-of-charge.

However, it's likely this cell has a protection circuit in it so you might
get away with it, but personally I'm not sure I'd want to risk it.

Theo

wrote:
Definitely a bit of an odd one this. The phone died last March (ish) with
the symptom of not charging - left on for a few hours, no charging led and
phone wouldn't turn on. Tried various chargers, leads, connecting it to a
couple of PCs etc. nothing. Looking online there were a number of reset
type fixes involving holding various button combinations, starting it
with/ without battery etc. and no sign of life.

I had something similar recently - brought old phone (Galaxy Note 4) out of
storage, battery flat. Left it on charge in a pile of stuff, went out for
half an hour. Came back, said it was fully charged - that was quick.

But, while the phone would power on, but was stuck in a bootloop. Tried
various things with reflashing the firmware (which all went through
successfully), still bootlooping.

Eventually I noticed the back cover was slightly loose. Took it off,
noticed the battery had puffed up. Evidently the battery only had a few
seconds of charge in it and as soon as it started to power on the phone
would brownout and reboot.

Mr Amazon supplied me with a new (Ravpower) battery and it was all fine
again.

Theo

On 31/12/2020 22:59, Theo wrote:


But, while the phone would power on, but was stuck in a bootloop. Tried
various things with reflashing the firmware (which all went through
successfully), still bootlooping.

Eventually I noticed the back cover was slightly loose. Took it off,
noticed the battery had puffed up. Evidently the battery only had a few
seconds of charge in it and as soon as it started to power on the phone
would brownout and reboot.

I think it is worth emphasising that this is indeed one way a LIPO
battery dies. Puffing and/or vastly reduced capacity. And vastly reduced
ability to supply current

In general, also, if you have gotten 5 years out of a lithium, you have
done well,

It is probably worth investing in a new one at that point anyway as you
are likely to have lost more than half the capacity.




--
I would rather have questions that cannot be answered...
....than to have answers that cannot be questioned

Richard Feynman