I wanted to post this 3 months ago, but is better later than never.
I hope some members find it usefull.
I got two Air batteries for tests.
One A1965 (for A1932/2179) and other A2389 (for M1 A2337).
Both are identical, only cable length different.
Use the same BQ24Z451, like any older MacBook battery.
Battery pack's V+ and GND connect to battery board (820-01654-A) with powerful copper strips (fig. 03).
VL and VG connect with low power rails, through the same flex where thermistors are placed (fig. 06).
For this reason, do not charge independent cells with high current using the points marked on the board; preferible less than 0.5A, only to revive hard discharged cells.
Higher current can be applied directly on the cells terminals.
Is possible (may need) to charge the pack directly between V+ and GND with higher current; not sure if this helps with heavy unballanced cells.
Bad/poor ballance usually denotes a bad cell, which should be replaced.
Battery pack uses 10K/25 degrees thermistors, in 0402 format (fig. 04).
They are protected against humidity.
However, I found one corroded in the A2389 (M1) battery.
Results that A1965 battery has one bad cell.
Just for test, I connected one small cell from an A1398's battery (fig. 07).
NLBA1 left me reset the battery; cleared errors and Locked changed to Unlocked then.
I was able to charge/discharge battery with NLBA1 normally.
I even tested few weeks later with an A1932 machine; worked good.
The M1's battery has problems with the electronics board (liquid spill); but seems to have good cells.
I then decided to interchange the boards.
Once connected the M1 battery with the electronics from A1965 battery, NLBA1 reported a bad ballance, with 2.5V on second cell and 3.5V (aprox) on the other two cells.
In such case, the reset function is disabled; requires at least 3V on every cell.
I forced the pack charge starting with 10V, going untill 11.6V.
Voltmeter showed all cells to aprox 3.6-4.2V and I reconnected the battery to NLBA1.
It allowed me to reset the battery then.
I started the calibration procedure and I got 97% healthy battery!
To use it in the same M1 Air A2337, it requires to replace the cable.
Or just use it as is, in Air A1932/2179.
All pictures in rar here:
drive.google.com
I hope some members find it usefull.
I got two Air batteries for tests.
One A1965 (for A1932/2179) and other A2389 (for M1 A2337).
Both are identical, only cable length different.
Use the same BQ24Z451, like any older MacBook battery.
Battery pack's V+ and GND connect to battery board (820-01654-A) with powerful copper strips (fig. 03).
VL and VG connect with low power rails, through the same flex where thermistors are placed (fig. 06).
For this reason, do not charge independent cells with high current using the points marked on the board; preferible less than 0.5A, only to revive hard discharged cells.
Higher current can be applied directly on the cells terminals.
Is possible (may need) to charge the pack directly between V+ and GND with higher current; not sure if this helps with heavy unballanced cells.
Bad/poor ballance usually denotes a bad cell, which should be replaced.
Battery pack uses 10K/25 degrees thermistors, in 0402 format (fig. 04).
They are protected against humidity.
However, I found one corroded in the A2389 (M1) battery.
Results that A1965 battery has one bad cell.
Just for test, I connected one small cell from an A1398's battery (fig. 07).
NLBA1 left me reset the battery; cleared errors and Locked changed to Unlocked then.
I was able to charge/discharge battery with NLBA1 normally.
I even tested few weeks later with an A1932 machine; worked good.
The M1's battery has problems with the electronics board (liquid spill); but seems to have good cells.
I then decided to interchange the boards.
Once connected the M1 battery with the electronics from A1965 battery, NLBA1 reported a bad ballance, with 2.5V on second cell and 3.5V (aprox) on the other two cells.
In such case, the reset function is disabled; requires at least 3V on every cell.
I forced the pack charge starting with 10V, going untill 11.6V.
Voltmeter showed all cells to aprox 3.6-4.2V and I reconnected the battery to NLBA1.
It allowed me to reset the battery then.
I started the calibration procedure and I got 97% healthy battery!
To use it in the same M1 Air A2337, it requires to replace the cable.
Or just use it as is, in Air A1932/2179.
All pictures in rar here:
Air batteries.rar
drive.google.com