bq27500 leaning cycle for creating golden image

Benjamin Wyrsch

Prodigy 60 points

Other Parts Discussed in Thread: BQ27500

Hello

I am using the bq27500 for monitoring the status of a Li-Ion battery pack (2 cell parallel).

Battery Pack: 1S2P ICR18650B4 (= 5200 mAh)

Chemistry ID: 230

Settings BqEasy:

Configuration
Parallel cells	2
Nominal Capacity	2600	mAh
min rated voltage	3000	mV
max Cell voltage	4200	mV
max taper current	200	mAh
max temperature chg	50	°C
min temperature chg	10	°C
min cell voltage system	3000	mV
max temperature dischg	60	°C
min average current dischg	500	mA
maximum current dischg	1700	mA
steandbycurrent	10	mA
SOC1 Alaram & BAT_LOW	100	mAh
SOCF Alarm Set:	60	mAh
SOCF Alarm Clear:	110	mAh
reserve capacity	50	mAh
constant power
fuel gauge disable charger if temperarture is outide charge suspension limits
BAT_LOW polarity	High
BAT_GD polarity	Low
Constant load with small load variations
Current sense resistor	10	mOhm
thermistor	Internal Sensor
Chemistry selection	Enable
Cell ID (very new chemistry)	230

Calibration done.

Problem:

Everything is looking fine, but i never see that the VOK & QEN bit goes to 1 by starting the IT-algorithm.

So the update status goes never to 1 or 2 and Qmax is never updated too.

As a result of that, the learning cycle fails.

But i see, that the fuel gauge is in a state of learning after enabling the IT-algorithm, because after one cycle the reported capacity is very accurate.

I am using a professional li-ion battery charger (cadex C7200).

Discharge current : 1.3 A

Charge current: 1.7 A

I am reaching all voltages and currents I specified in the configuration during charging and discharging (FC & SOC1 & SOCF are correctly driven).

There is no RUP_DIS, no other malfunction, ....

It would be great, if you could help me with finding the problem I have.

Thanks a lot!!!

Here are some screenshots I did:

(Next time I will log all data during the whole cycle)

FLASH Calibration:

FLASH Configuration:

RAM Before Step 1: