Battery fixed at 71% for the last two weeks and counting. MJWSD06MMC

[GAZ082]

Hi there. I've been using this new firmware with TWO brand new MJWSD06MMC and noticed that the battery level has been fixed to 71% for at least two weeks.

1. Odd that brand new (purchased this year in ALI) batteries are 71%, but can happen i guess.
2. Voltage is 2.770V and 2.773V (different voltages, that's good).
3. The Advertisement webapp also shows 71%.

Any tips? Thanks!

[pvvx]

The MJWSD06MMC contains a 2.8V voltage regulator chip. This increases battery consumption.
The firmware is designed to be removed from this unnecessary chip and measures the actual power supplied to the chip.

[GAZ082]

Thanks Victor, let me see if i understood what you said:

• It has a voltage regulator that has to be removed for the firmware to pick up the correct battery level?
• If so, can I calculate the battery level myself taking as 100% 2.8v? and using the voltage value from the sensor?
• I'm not an expert with soldering, i may mess it, is there a considerabe automony gain if i remove the regulator?
• Where is the vreg chip? I asked Gemini and indicates the chip on the top left, but that seems to be the LCD driver :)

[pvvx]

I use this modification:

The XC6206P282MR SOT-23 packaged chip is removed and a jumper is installed.

The voltage divider resistors are connected directly to the battery and draw a current of approximately a few μA. One of the resistors is removed.

But with this modification, the original Xiaomi firmware will assume the battery is dead...

These changes reduce the current consumption by ~3..5 µA in the device's sleep mode and by a difference in the efficiency of the integrated DC-DC converter during active operation.
And the operation will continue at a lower battery voltage ( - voltage drop on the stabilizer microcircuit).