Dell Vostro 15 no charge

[dclass-pro]

Hi guys happy new year to all,
I have a problem with a DELL Vostro 15 (code on main 3263) that doesn't increase the battery percentage.
Its original battery is dead, I changed it with 2 compatible batteries, the pc sees the battery also from the bios and says everything is ok, but when I put it on charge it always stays fixed at 71%, I measured the voltage across of the battery and 15V arrive only when the battery is inserted, there are also 3.3v on the central poles of the data exchange. What can it depend on?
I am attaching the wiring diagram. Thank you all

[mon2]

Re: Dell Vostro 15 no charge

Remove the smbus ESD diodes at D4305 and D4306 and test again.

[dclass-pro]

Re: Dell Vostro 15 no charge

I removed the 2 diodes and it still doesn't work...

[mon2]

Re: Dell Vostro 15 no charge

Measure the voltage to ground of each pin on the BATT1 connector.

Confirm the same voltages are present on the other side of RN4302.

Do check for corrosion in this area. Confirm the battery contacts are mating.

The battery properties are extracted over the SMBUS interface and is with the BMS module inside each battery pack. If the interconnect is not defective then the MEC may be at fault. Wait on others to comment if that device is programmable or not.

[dclass-pro]

Re: Dell Vostro 15 no charge

i confirm that the voltages are ok and RN4302 is ok, maybe it can depend on the MEC, but maybe can look for the original battery?
Can I reassemble the 2 diodes D4305 and D4306?

[mon2]

Re: Dell Vostro 15 no charge

Yes, place them back. Sometimes, the esd diodes impact the SCL or sda lines and corrupt the communication between the MEC and the BMS module.

With your case, can you check the details of you battery? Such as serial number, number of charge cycles, etc. ?

Using an Arduino, you can do this.

Have linked the github article on this topic in this forum. It is possible that the battery is a fake. You can try another brand from Amazon and return it if it does not work.

[dclass-pro]

Re: Dell Vostro 15 no charge

yes i already tried a new battery but i have the same problem

[mon2]

Re: Dell Vostro 15 no charge

Then it appears to be down to MEC controller which is the smbus master. Do you have a scope or bus analyzer? Even a $5 usd bus analyzer from AliExpress can work to monitor the smbus lines. Then you can confirm if the MEC is communicating with the battery pack or not.

Using an Arduino, you can confirm the serial number, etc of the battery pack.

https://github.com/ArminJo/Smart-Bat...fo_For_Arduino

[dclass-pro]

Re: Dell Vostro 15 no charge

I don't have arduino but I have an oscilloscope and I can check if there is data exchange, but I think there is otherwise it wouldn't have seen the battery.. it's a strange defect

[mon2]

Re: Dell Vostro 15 no charge

Yes, do check for pulses on the SCL and SDA pins.

The battery detect is a single pin status check at PBAT_PRES#. If this pin is LOW = 0 volts (active low signal), the battery is considered to be present.

Of concern is why the battery gauge remains a fixed value. This is a digital value to be read over the SMBUS interface. Then the firmware inside the MEC (8051 microcontroller) converts the binary value to a charge percentage.

[dclass-pro]

Re: Dell Vostro 15 no charge

I confirm that the data exchange on the 2 pins of the battery is there, perhaps it requires the original battery..

[mon2]

Re: Dell Vostro 15 no charge

Yes, try a different brand or if possible, the original battery.

[dclass-pro]

Re: Dell Vostro 15 no charge

I also tried with its original battery and it has exactly the same problem, data exchange present but it does not charge ... I try to order the new original one and I will let you know

[mon2]

Re: Dell Vostro 15 no charge

Which line did you probe with the scope? SCL or SDA ?

Check to see if there are similar pulses on the other SMBUS interface line.

[dclass-pro]

Re: Dell Vostro 15 no charge

I probed both lines

[mon2]

Re: Dell Vostro 15 no charge

Should have asked earlier, are you using the recommended and official power adapter for this unit ?

The logic board does ping the power adapter for the power rating using the PS_ID single wire interface.

If the PS_ID line is defective (??) or the wrong adapter is used, the battery will not charge.

Can you measure the voltage to ground of the PS_ID line for the power adapter?

[mon2]

Re: Dell Vostro 15 no charge

See attached for test points of interest.

If the host logic board is unable to properly detect the power adapter, the battery will fail to charge.

[dclass-pro]

Re: Dell Vostro 15 no charge

I use the original charger and I also tried another original charger, same result.
On the 2 points you ask, I have 3.2V

[mon2]

Re: Dell Vostro 15 no charge

Does the BIOS report the details of the power adapter?

If not, remove PQ4301. Then bridge the source & drain pins using the PCB pads for PQ4301. You may be able to do the same with a solder blob @ PR4306.

Confirm the resistance of PR4305 against the schematic value.

[dclass-pro]

Re: Dell Vostro 15 no charge

I confirm that in the bios it shows the values of the power supply and that the PR4305 resistor is 33ohm