Hello,
I have been testing a Seeed Wio Tracker L1 Pro powered only by its original solar panel and battery.
I consistently observe the following behavior:
- The device charges normally when it is cool.
- After being exposed to direct sunlight and the enclosure becomes hot, solar charging stops.
- The battery then starts discharging even though there is still strong sunlight.
- When the device cools down, charging starts again.
I checked the hardware and found that the L1 uses a CN3165 solar charger with a 10k B3950 NTC.
I also performed another test:
- I disconnected the original charging circuit.
- I connected the same battery and the same solar panel to an external CN3791 solar charger.
- With the external charger, the battery continues charging under the same sunlight conditions.
This suggests that the battery itself is probably not the cause.
Could you please clarify:
- What are the temperature limits used by the CN3165 implementation on the L1?
- Is the NTC measuring the PCB temperature or the battery temperature?
- Is this expected behavior?
- Can the charging temperature limits be changed by firmware, or are they fixed in hardware?
Thank you.