On Tuesday, February 27, 2018 at 8:31:24 AM UTC-5, Ross wrote:
Uli,

You are looking for a 3,6v Litium battery.

https://www.ebay.de/itm/Saft-LS-1450...AOSwzb9ZpXm 4

Remove the top cover and you will see it at the back, both ends bent down and soldered to the board, and the sides bonded with silicon

Perfect - thanks, Ross! I saw that component but being more of a 'Nuts & Bolts' guy, thought this is a big resistor or capacitor. :-)

Uli
'AS'