Other Parts Discussed in Thread: BQ40Z50-R2, BQ40Z50, EV2400
Hi team,
The customer use BQ24171 as a charger to charge a battery, battery use BQ40Z50-R2 as management IC. charger output 12.6V, the battery rated voltage is 12.6V.
There is a phenomenon that the charging LED will off (STAT pin control) when charging last over 8 hours and under 10 degree environmental temperature, when environmental temperature above 10 degree, the charging LED will still on and give out a right charging status. when LED off, the charging stop at same time.
The LED will still off(charging stop) even temperature rise up to 25 degree. charger or battery can not wake up by themselves unless battery re-plug.
Issues:
1. Why the charging LED off(charging stop) only happen with environmental temperature below 10 degree ?
2. Which IC , BQ24171 or BQ40Z50 cause this LED off under 10 degree temperature?
3. Why LED off phenomenon happen after charging time over 7 hours? why not happen in a shorter time?
4. Could you recommend a tool to analyze this issue?
NOTE:
The BQ24171's TS pin configuration : RT1=2.2K, RT2=6.8K, RTH=10K.
The TS voltage is still below 2.32V, Vref=3.3V under low temperature environment.
The voltage of battery is about 11.7-12.1V after LED off (charging stop), full charged battery voltage should be 12.6V.
Could you help check this case? Thanks.
Best Regards,
Cherry