Today I discovered that one of the SI BSF8 stations (serial number 111515) on which I updated the firmware to 6.23 a few weeks ago was behaving strangely and that the voltage reported by SI Config was 1.64 V. With such a low voltage, the processor can hardly run and the beeper will probably not beep, at least not as loudly as it did.
This all sounds like a known bug that sometimes occurs after updating to 6.23. The Sportident release notes for firmware 6.23 says:
Very low battery voltage indicated
After booting to firmware 623, it can happen in rare cases that the device indicates a very low battery voltage. Config+ will show “(invalid)” for the battery voltage. This is a measurement error of the station. As a workaround, you should use the “Factory reset” command in Config+. This will reset the device and should fix the voltage value.
I opened the unit up and found that the sleeve of the battery was cracked, but that there were no visible signs of corrosion or other problems, unlike in a previous station. The idle battery voltage was 3.46 V.
I followed the recommendation in the release notes and used SI Config+ to do a factory reset of the station and after that the reported battery voltage was a much more realistic 3.17 V. A few minutes or so later the voltage was up to 3.25 V (a case of “voltage delay” in lithium thionyl chloride batteries).
I hope the station stays in the sane state and that the Sportident developers soon figures out and solves this bug.