8310 backup battery not charged?????

I have a water damaged 8310, which seems that the backup battery for the clock is not working (each time when i remove the battery at the back and insert the battery, the clock shows back to 09:00), i've checked the voltage and it's 2.6v. Is this the corerect reading?
If not i assume that there is a broken circuit to the battery. Could somebofdy post the wiring (jumper( diagram to me?

Thanks In ADvance

I've the same problem like you have!
Please help!