Hi Team,
We’re using the BQ24072 to manage a custom Li-Ion battery pack, supplied by BAK.
The product is now in the final stages of EN60950 safety approvals testing. The test house has observed that the quoted maximum charging temperature for the battery is 45degC, which seems to be the commonly used upper limit for charging of Li-Ion cells.
They questioned why our product’s quoted operating temp range is 0-60degC. Our immediate answer to this is that the battery charging chip inhibits charging at higher temperatures by monitoring the thermistor in the battery pack.
From the datasheet:
“The bq2407x features an external battery pack temperature monitoring input. The TS input connects to the NTC thermistor in the battery pack to monitor battery temperature and prevent dangerous over-temperature conditions. “
However, we’ve just noticed that the BQ24072’s default cut-off temperature for charging is 50degC, not 45degC.
It seems the chip design doesn’t allow for this threshold to be reduced (only extended).
We’re wondering why the chip defines 50degC as the cut off, whilst Li-Ion battery chemistry requires a threshold of 45C.
Anything you can add which might help us here?
Thanks in advance,
