We planned to sense insertion of a battery into the charger by reading the voltage derived from TS. However the data sheet shows the limits on REGN to be 5.6 to 6.65V and battery presence must be sensed at temperature down to 0°C. The combination results in limit values for not present and for present at low temperature to overlap. To simplify the solution it would be helpful to know whether the actual distribution of devices in your production (for ~ 1 mA load and with 12V input ) is much tighter than the published range, and will not change significantly on future production.
For example; If 99.5% of units will fall within 6.0 +/- 0.2V and that will remain correct for years to come, that would avoid our having to develop a different type of solution.
Thank you,
Lon