The bq25504 data sheet on p.15 has a caution that (paraphrasing) "if VIN_DC is greater than VBAT_OV, ...the input pinVIN_DC is shorted to ground...the source impedance must not be a low impedance source."
I want to use a PowerFilm thin-film amorphous solar cell MPT3.6-75 which has a VOC of 3.6V. And set VBAT_OV at 3.3V (as the evm is by default configured.)
The application is in low light (indoor artificial light, or possible a bright window.) Under such conditions, the solar cell would not be putting out much power or voltage.
But in full, direct sun, I suppose the solar cell would put out 3.6V, open circuit.
I am not an electrical engineer, I am having trouble conceptualizing the danger. Open circuit means an infinite resistance load and no current. But the bq25504 is shorting it, so it would be at short circuit conditions, which is high current and 0V from the solar cell (put also 0W power.) What is the impedance of the solar cell under short circuit? But if it is at 0V, why would the bq25504 continue to short it?
Is there another way to characterize solar cells that exceed the bq25504 capabilities?