Battery voltage alarm on OSTC3 with fresh battery

[hdohlmann]

Recently, my old OSTC3 has started showing lower-than-actual battery voltage.
And, during dives, the voltage is reported even lower, with yellow warning-triangle and red warning text.

This is with a fresh SAFT LS14500 3.6V battery.

At rest, it shows 3.41V (T1).
During dives it shows 3.1V with warnings.

Is this a known issue?

OSTC3
Firmware 3.37
Serial: 2820
Hardware: 0E80-F205
Hardware: 6008/0016
Sensor: 09Ca-6D40

[hdohlmann]

I just put it in USB mode and downloaded the latest batch of logged dives.
I noticed that now the voltage is 3.51V.

Detaching the usb cable again, and not it's back at 3.4.

This seems to be consistent.
When plugged into an USB port on my computer, voltage shows 3.51V.
When unplugged it shows 3.41V.