Full cycle: Hard discharge. Full Charge

Cell voltage comparaison

Event	Highest Cell ID	Highest Cell V	Lowest Cell ID	Lowest Cell V	Diff V
Before discharge	C7	4.135	C5	4.116	0.19
After full charge & relax time	C7	4.186	C5	4.159	0.27

💡

15A discharge for ~33mn didn’t unbalanced cells enough to trigger balancing algorithm. This test unbalanced cells for at most 0.08V. Discharge had few problem at the end. Charge went well.

Discharge phase

Cells Voltage during discharge:

	Time (s)	C0	C1	C2	C3	C4	C5	C6	C7	C8	C9
Before discharge	3	4.131	4.133	4.130	4.132	4.131	4.116	4.133	4.135	4.132	4.133
Just before end of discharge	1988	3.022	3.007	2.995	2.962	2.991	3.033	3.056	3.036	3.062	2.985
Just after end of discharge	1994	3.235	3.243	3.245	3.257	3.242	3.244	3.276	3.276	3.282	3.266
Pause after end of discharge	2153	3.385	3.395	3.393	3.398	3.396	3.375	3.401	3.396	3.407	3.393

Discharge lasted ~33 minutes (1989).

At the end of charge, we get the following errors:

shortCircuit ❌

Seems weird to have this here.
I think: cellUnderVoltage turned DSG FET off. cellsOvertempInCharge turned CHG FET off. So we have both FETS off. As in the logs. Next, cellUnderVoltage stopped, causes DSG FET to turn on. (We don’t see that in the logs, it must have been too quick). And turning only DSG FET ON while still connected to a load, triggers the same error as the predischarge always-on error, and we have a shortCircuit.

cellUnderVoltage ✅

This is why the charge ended. It’’s the expected behavior.

cellsOvertempInCharge ✅

As we watch all errors and cells were almost over 50°C, it seems OK.

Detailed logs

c++
1	"Entered state INIT"
1	"Log: 'Initializing environment...'"
1	"Log: 'Environment initialized !'"
1	"Log: 'Initializing battery IC...'"
1	"Log: 'Battery IC initialized !'"
1	"Log: 'Configuring battery IC...'"
2	"Log: 'Battery IC configured !'"
2	"Log: 'Initializing SoH...'"
2	"Log: 'SoH initialized !'"
2	"Log: 'Waiting for BQ cells readings...'"
2	"Log: 'Initializing SoC...'"
3	"Log: 'SoC initialized !'"
3	"Log: 'State fields initialized!'"
3	"Log: 'Battery initialization complete!'"
3	"Left state INIT"
3	"Entered state DISCHARGE"
3	"Log: 'transitioning from INIT to DISCHARGE'"
1989	"Left state DISCHARGE"
1989	"Entered state ERROR"
1989	"Log: 'transitioning from DISCHARGE to ERROR'"
2150	"Left state ERROR"
2150	"Entered state DISCHARGE"
2150	"Log: 'transitioning from ERROR to DISCHARGE'"

21-09_discharge.dat

2252.5KB

Charge phase

Charge lasted ~296 minutes (17757s).

	Time (s)	C0	C1	C2	C3	C4	C5	C6	C7	C8	C9
Before charge	2756	3.451	3.453	3.452	3.454	3.453	3.445	3.454	3.452	3.455	3.451
Just before balance-only mode	20213	4.195	4.199	4.197	4.200	4.198	4.174	4.200	4.202	4.200	4.199
Just after end of charge	20516	4.187	4.191	4.188	4.191	4.189	4.166	4.192	4.194	4.192	4.191

Detailed logs

c++
2757	"Left state DISCHARGE"
2757	"Entered state CHARGE"
2757	"Log: 'Charge enters charge-and-balance mode'"
2757	"Log: 'transitioning from DISCHARGE to CHARGE'"
20214	"Log: 'Charger has not enough current: -0.010000'"
20214	"Log: 'Charge leaves charge-and-balance mode'"
20214	"Log: 'Charge enters balance-only mode'"
20514	"Log: 'Battery is balanced'"
20514	"Left state CHARGE"
20514	"Entered state DISCHARGE"
20514	"Log: 'transitioning from CHARGE to DISCHARGE'"

21-09_fullcharge.dat

17896.0KB