It is a MacBook Air with the iPhone Like Batteriy Connectior, i definetly connected it properly (also cleaned the contacts)

I2C lines are also alternating between 2 voltages if charger and battery is plugged in

Thank you for the quick answer. They are about 1.6V for scl und 1.4
v for sda in diode mode, openline in resistance mode

Hi,

i have a Macbook air M3 15 inch (820-03286) which had some water damage, everything works now but battery charging. Sadly i currently do not have another Battery to test, and want to find out if Battery behaviour is normal before wasting time searching for non existant board problem. Cell voltage is 3.7V for each single Cell but shorting SYS_DETECT_L does not result in any output voltage. Is 3.7V to enable output with SYS_DETECT_L shorted? Macbook shows 65536 Cycles and service recommended so i2c communication seems to be broken. If battery is disconnected it shows normal values...