HP Pavilion 14 chewbacca_14_u_uma battery charging problem

[lietuvis10]

Hello guys, I'm having problem with this laptop. The battery is not charging, but system seems to recognise it via AIDA. The indicator on charging port seems to work fine, when plugging in battery it goes orange and when removed - white.

The charging chip is BQ737.


Voltages (battery plugged in):

1. ACN - 19.66V (19.6)
2. ACP - 19.65V (19.6)
3. CMPOUT - 0V (0)
4. CMPIN - GND
5. ACOK - 0V (0)
6. ACDET - 2.61V (2.61)
7. IOUT - 0V (0)
8. SDA - 3.3V (3.25)
9. SCL - 3.3V (3.3)
10. ILIM - 3.29V (3.29)
11. BM# - 0.65V (0.4)
12. SRN - 0.931V (10.49)
13. SRP - 0.942V (10.69)
14. GND
15. LODRV - 0V (0)
16. REGN - 6.04V (6.04)
17. BTST - 7.07V (10.62)
18. HIDRV - 0.982V (10.90)
19. PHASE - 0.981V (10.90)
20. VCC - 19.63V (19.64)

There is no scheme, just using other laptop one:

[KvnTM]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Does windows recognize the battery and show a percentage?

Phase is the charging connection to the battery which is 10.9V. So the battery is at 10.9V which is really low in my opinion. I guess it refuses to charge the battery because of protection.

Fully charged voltage of that pack would be 14.4v (4,8V/Cell assuming the pack has 3 cells in series)
10.9V/3 would be 3.63V/Cell which is just around the cutoff of 3.7v.

I'd charge the pack externally a little bit until the voltage goes above 12v.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

yes it shows percentage, shows that charger is plugged in but thats all

doesn't say it is not charging or either charging

[KvnTM]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

yes it shows percentage, shows that charger is plugged in but thats all

doesn't say it is not charging or either charging

I edited my last reply in case you missed it.

EDIT:
My last reply won't be the issue here.
I just noticed that ACOK is 0v.

The data sheet says:
AC adapter detection open drain output. It is pulled HIGH to external pull-up supply rail by external pull-up resistor when voltage on ACDET pin is between 2.4V and 3.15V, and voltage on VCC is above UVLO and voltage on VCC pin is 275mV above voltage on SRN pin, indicating a valid adapter is present to start charge. If any one of the above conditions can not meet, it is pulled LOW to GND by internal MOSFET. Connect a 10kΩ pull up resistor from ACOK to the pull-up supply rail.

This indicates there's a problem somewhere else.

"voltage on VCC pin is 275mV above voltage on SRN pin."
VCC is 19.6V
SRN is 10.49.
There is a problem. SRN should be 275mV lower than VCC.

[piernov]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Did you try a known good battery?

EDIT: 14.4V packs are 4 cells in series, nominal voltage of 3.6V per cell.

[KvnTM]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Did you try a known good battery?

EDIT: 14.4V packs are 4 cells in series, nominal voltage of 3.6V per cell.

I got that wrong. I forgot the nominal voltage isn't the charged voltage. Oopsie.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

I have charged the batteries before, they were @ 50% but did not charge.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

This battery was charging before, it charged once to 97% percent, everything was fine and after trying to charge it for second time it didn't charge at all.

I have 2 batteries from GREENCELL, both of them are non working.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

ACOK should be 0V since its inverted signal, when removed AC - it goes to 3.3V

Correct me if im wrong.

[KvnTM]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

If any one of the above conditions can not meet, it is pulled LOW to GND by internal MOSFET.

Datasheet says if any of the mentioned signals is out of spec it pulls ACOK to gnd indicating something is wrong. The SRN pin is not what the chip expects so it throws an error (ACOK pulled to gnd).

......and voltage on VCC pin is 275mV above voltage on SRN pin, indicating a valid adapter is present to start charge.

If all conditions are fine ACOK will stay high.
Your SRN pin is way out of the condition requirements so it pulls ACOK low.
I think it has something to do with the charger detection.

[piernov]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Both batteries could be bad. Are they both fully discharged? If not, does it work from battery, AC adapter unplugged?

@KvnTM
You may be looking at the wrong datasheet.
On bq24737, ACOK# is indeed active low. Meaning that it should be 0V when working properly with AC adapter. ACOK# will command the gate signal of the P-channel DC-in MOSFETs.
SRN is one of the current sense input for battery rail, so it'll have almost the same voltage as battery voltage.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Both batteries could be bad. Are they both fully discharged? If not, does it work from battery, AC adapter unplugged?

@KvnTM
You may be looking at the wrong datasheet.
On bq24737, ACOK# is indeed active low. Meaning that it should be 0V when working properly with AC adapter. ACOK# will command the gate signal of the P-channel DC-in MOSFETs.
SRN is one of the current sense input for battery rail, so it'll have almost the same voltage as battery voltage.

Yes, it works from battery without AC, it discharges as normal, but when connecting the AC it does not charge just stays same percent as if it starts to work from AC only.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem



here is a pic of an AIDA info I get. At the bottom it says 62%, plugged in.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Any advice?

[KvnTM]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Does the charger have some sort of data/identification pin? Maybe try another one.
Also you are using 3rd party replacement batteries which could be the cause.

Any chance you can get hands on a oem battery + different oem charger?

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

I have tried 3 different chargers, all the same. I have ordered another motherboard and will try to identify the problem, will see if it's the battery fault which I think is not faulty (because it works fine, discharges, can charge it normally with PSU).

[mcplslg123]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Your high and low side fet gates are not opening as per your readings of bq737. did you checked those fets or replaced them??

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

Hello mcplslg123, do you mean these fets? I thought about them, and haven't check them yet.

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

checked those fets:
both are n channel aon 7408

first one(with battery):
S: 5V (11.8) G: 5V [before it was 2v?] (11.8) D: 19V(19)
second one:
S: 0V (0) G: 0V (0) D: 5V [before it was 2v?] (11.8)

[lietuvis10]

Re: HP Pavilion 14 chewbacca_14_u_uma battery charging problem

and after replacing BQ it started to charge strangely ???