• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

Help T989 Temperature Sensor Battery Charging Issue

M

moonie

Newbie
Have an issue I believe with the T989 battery temperature sensor or thermocouple (T/C). The symptom is that after I plug in the charging cable in about 5 to 6 sec I get a warning message that the battery is too hot and charging is stopped.

I know the battery is at room temp and I have used 5 batteries all with the same result. I know the micro-USB port is OK because I can run Kies on the port and transfer gigs of data with no issues.

The T/C is a little cylinder on mobo near SD card slot I have been told. I have cleaned out the T/C with alcohol and compressed air several times to no avail.

Can I replace the T/C without replacing the entire mobo? Can I turn off the temperature sensing sw so this warning and charging shutdown does not occur?

If I can do either if these things as much detail as possible to howto would be much appreciate.

I work in the battery business so I am not concerned with safety issues as I will self monitor the charging. I can charge the battery out of the T989 but need to solve this issue so I can charge the battery in the T989.

tia
 
Are you sure that your phone uses this TC to measure the battery's temperature? ... and doesn't use the battery's build-in thermistor for this?
If it would use the thermistor's contact a slight chance might be to look on the phone's battery booth/bay for corroded contacts.

Harry
 
Yeh, the battery contacts are pristine. Also I have used five different batteries all with the same result - charging starts then stops 5-6 seconds later.
 
Okay, these contacts in the battery bay are pristine ... so there might be a bad or brocken connection where the contacts fixed on the mobo.

See, I don't think that the sensor for measuring the battery's temperature is outside of the battery. I think it is inside and connects to the phone's charging control by one of the two contacts between the battery's power and ground contacts.
And if the charging control detects nothing or near to nothing for calculating the temperature it will stop the charging.

Harry
 
The S4 shows the ambient temperature.
Does the S2 too?
If so, that TC might be for measuring ... or it might not be a TC at all ;)

Next time I'll have a look at a friend's S2 :)

Harry
 
If there is a app that will display the t/c reading - tempature - that would be a way to verify the t/c is working. I could hit the t/c with LN and a heat gun to see it move too.
 
moonie said:
If there is a app that will display the t/c reading - tempature - that would be a way to verify the t/c is working. I could hit the t/c with LN and a heat gun to see it move too.
Click to expand...
The app Battery Monitor Widget could show you the (from phone measured) temperature of the battery, even on a graph by time.

But again, I think the temperature sensor is build in the battery.
Your battery has four contacts, + and - power, temperature indicator and the 'Battery Size Indicator'.

This screenshot is from a Panasonic info sheet about their Li-Ion batteries ...
zu4y4ara.jpg
Harry
 
Cleaned phone battery contacts with alcohol and blew out with compressed air. Did not check the battery contacts for signals with a Fluke to see if they are sending signals. Figure I would do that with a battery app as it must have proper signals to display battery temp.

Now to install battery widget without a sims card. Maybe down load to PC and Kies it over as working via wifi from the T989 seemed problematic.
 
I think that the phone gets a tampered signal for calculating the temperature.
So I'd guess that Battery Monitor Widget will show a temperature above 45
 
Ok installed the BatteryBot Pro version and ran/installed five different batteries from three different suppliers - one was even a double capacity battery.

All the batteries showed a discharging temperature of 65.0 C which is 150 F. No way any of the bats were at this temperature. The widget did display battery voltage which were correct as verified by the Fluke meter.

Therefore either a) the signal is not being sent and the Andriod OS sw defaults to 65.0 C or b) the signal processing of the battery T/C signal (assuming its an analog voltage signal) is all messed up.

The BatteryBot Pro widget said it display's battery voltage and temperature from the Android OS. I can email the developer for more details on this if we need to.

More info on problem so we may be getting close to the solution. I know I'm learning allot too. :)
 
Next step might be to know the battery's pinout. Power + and - contacts are printed on the battery, but there are also Btemp and BSI contacts. You've to know which contact is Btemp, maybe it's possible following its signal path.

I'm assuming too its an analog voltage signal :) The thermistor inside the battery is grounded on the battery's "-" and therefore the Btemp contact on the phone's side should be bridged with a resistor to battery's "+" (or phone's +5V ?). So this Btemp contact would be the midpoint of a voltage divider and should have a floating voltage, level proportinally by the battery's temperature.

Harry
 
Excellent input. I will do the following today:

1) Measure the voltage between the temp (thermistor) signal contact and each of the battery terminals which are marked. I have a different Samsung battery from another device that is exactly like the T989 batteries I have but it only has three top connectors on its battery. This three connector battery runs the T989 just like the others A-OK but for 65.0 C temps. Its center connector will be my first choice for thermistor readings. I will hit the battery with LN and a heat gun to vary its temp and record the voltage changes.

2) Email the Batterybot developer because since the 65.0 C readings I always get looks like some default constant value if a signal is not on the battery leads. If I had a working Galaxy I would tape over the temp connector of the battery and see if the problem is duplicated on that Galaxy.

Assuming (bad to do) I get a varying voltage signal with bat temp and the sw developer says the 65.0 C reading is what is given when no signal is given then I most likely have a contact problem on the T898 or the circuit that does the A/D of the battery thermistor voltage signal is hosed.
 
If this three contacts battery fits in your phone then the other batteries should have a pinout like
1(+) 2(BTemp) 3(-) 4(BSI)
right ? :) sorry, just for my curiosity ;)

Harry
 
Yes the pinout is exactly as you stated.

I was not able to get the ohms from pin2 to pin3 to ever change. The ohms always stayed at 1.5 k-ohms. Hit it with a heat gun, LN and shorted the bat with a lamp and then a copper wire. Ohms never changed. ????

I don't know how temp signal is used let alone sent now.
 
UPDATE:
In a German forum a poster slaughtered his S2's battery ... and found not a thermistor!
The pinout is
1(+) 2(BSI) 3(-) 4(nc)
BSI's resistor has 1.5kOhms and indicates the battery's capacity of 1650mAh.
In the forum they think there has to be an external temperature sensor near the battery for the phone to calculate the battery's temperature.

So you and dingowarrior were right from the beginning.
I beg your pardon for misleading you!

Harry
 
Excellent post and find. Facts are lining up.

My guess is the sw developer will say his BatteryBot widget get battery temp from an Android object - i.e. OS sw.

We may now need the help of an Android person and source code. Now its getting real interesting.

No need to apologize - we all seek the truth and in all worthwhile quest's for truth the path is usually never straight.

:)
 
Found this but I beleive this is a pre-Android phone. I do not beleive Android has secret internal menus.

“Charging paused. Battery temperature too high or too low”

When I was searching through the web I found than someone had found a solution for other Samsung phone (he did not mention what model it was), and the solution was as follows:
“I noticed there was some internal phone menus dealing with charging temperature. Using this method I was able to resolve my problem for now:

step 1. *#197328640#
step 2. [9] common
step 3. [1] Batt, Temp
-> next to Batt temp ADC it said 254 for me. Obviously it's incorrect, I think the sensor for the battery temp somehow messed up. Take note of that number.
step 4. Go back to the main menu and select [2] Version Information
step 5. [4] Charging Temperature
step 6. I changed [1] high stop to 255 and [2] high recover to 254.
With those changes, my phone now actually charges off the wall and car charger. Anyways hopefully this helps someone.”
 
Looks like these *#*#...#*#* dialer codes that might give info by the OS but can't change anything.

But even if you'd be able to cheat the OS you'd be pretty sure that the battery would manage heat problems by itself and the phone would use the Btemp pin only for temperature info.
Batteries with an internal thermistor can/might do this, but we don't know it for sure.
But see, your Samsung battery seems to be even depent on external temperature sensor.

Harry
 
Well the temperature sensor has a reading of 3.5+/- 0.1 ohms between the outer casing and the inner hole. I am assuming it is a thermistor. I however could not get the resistance to change at all with varying it's temperature. This means it is broken or it is not a thermistor and/or the temperature sensor.

As far as the sw fix that will take a little longer to research. You can get all the source for Jellybean but it is non-trivial to access it. Also to recompile it you need a Linux box or Mac. I have access to a Mac but recompiling Jellybean with the mods is also non-trivial, let alone loading it on to the phone.

Wish I had more info so the path taken makes more sense.

Wondered if a total sw reset would fix the problem?
 
A factory reset might be worth to try :)
At least you'd know for sure that it's not a software issue ...

Harry
 
You must log in or register to reply here.
Back
Top Bottom