Hello,
on a board i use a combination of bq25886 and a bq28z610r1. For the most parts of our testing procedure every think works as expected.
For example a normal load cycle at 26 °C :
But at low temperature i have some unexpected behavior:
- because the temperature is below 10 °C the charger only charge with reduced current (JEITA Mode: 20% from ICHG = 1A *0,2 = 200 mA ) -> OK
- max charge voltage: 8,4 V -> OK
- normal termination current (ITERM) :100 mA -> not OK
At normal temperatures the termination current was around 100 mA, so my expactation was, that the charger always stops at 100 mA independent of the temperature. My next thought was, that at low temperatures the termination current is calculated from the reduced current so the charger will stop at 20 mA. But this also not happend. The next idea i had was: look at the datasheet. The datasheet point out that the termination range is 10 ... 800 mA. But again no stop at 10 mA.
The question is:
- Why does the charger not stop at 100/20/10 mA at low temperatures?
- When does the charger reach "charge termination" at low temperatures?
Note: charging picture with zommed in current (i canceled the test at around 5 mA charge current)
