I am having some difficulty getting a board that has a Dallas Real Time Clock DS12C887+ to behave. The DS12C887+ has an onboard (and inaccesible) battery that is molded in. My suspicion is/was that the battery in it is flat. I have filed two slots in the side of the RTC and exposed the battery terminals. I get 2.92V from the RTC (using a Fluke 87 III which i think is fairly accurate). Would this be sufficient voltage to reliably operate the RTC or is it a bit too low. I can piggyback a Li-Ion battery as has been done by others (CR2030 or equivalent 3V which actually reads 3.2v) onto the RTC by gluing a button battery holder in place and soldering a couple of pigtails to the terminals i have exposed and then cutting the existing battery out of circuit. The manufacturers datasheet for the RTC can be found by searching "DS12885-DS12C887A.pdf". Does anyone know if 2.9V is enough to keep the RTC running reliably? Many thanks. Halsey