PIC and RTC DS1307 problem - hardware vs software ?

[jorge]

I had a similar issue several years ago with a 1307. I can't explain exactly what the problem was, but putting a 1uF very low-leakage cap across the battery solved the problem. An added benefit was that - if you were quick, you could change the battery without clearing the clock. The chip will run on the capacitor alone for 10-20 seconds. The cap has to be low-leakage, otherwise it will drain the battery.

I cant find a cap like the one you said - 1uF very low-leakage cap-
i tried at Farnell, digikey and so on...but if you could provide me a direct link or even a full spec of one would be great..otherwise i am afraid of it draining the battery !

Also i already have lots of caps both in the power supply , lots of 100nf on the pcb board, the standard ones on LM7805 , and so on..
My biggest problem is that i cannot simulate it , and as so i cant provide a valid software workaround to the RTC stop/ it just freezes time without any reason.
( note: i ve already replaced the board and the DS1307, check the value of all the resistors ( 10K ) , check and changed the RTC OSC, redesign PCB in terms of ground and power lines, check solders, and so on....felling lost now)

thanks for your help.

note:
Darrel , MisterE , & other PRO´s: any miracle software workaround you can think for this -the freeze time on the RTC ? Maybe using the PIC EEprom and an pic check stall time function...i am just worried that this way i will kill my EEPRom sooner or later
I already have a auto set date/time when it has garbage settings inside but not when it simply stops without a reason.
Damm i hate these DS1307 things

[Charles Linquis]

The cap we use is actually a .47 uF ceramic

TDK P/N C3216X8R1H474K