CMOS Battery has begun to Discharge to quickly

[LesD]

I have a Jeyway 663AS Pro MoBo with an AMD Athlon 1.4 Ghz Thunderbird Processor on it, the 100/200 MHz FSB one.

This Mobo has the VIA Apollo KT133 chipset and worked well for many years in fact the MoBo still works fine once it is booted up. The problem is that I keep having to put new CMOS batteries in it. The first one lasted for years the next one about 6 months and the last one or two less than one month. I have tried batteries from different sources studied the Mobo for foreign matter that could be draining the battery all with no success. 

I have Googled extensively and found some suggestions like building a simple rechargable battery circuit, adding a couple of C cells in series with a much larger capacity to snipping and replacing the diodes down by the battery.

Can anyone recommend the best approach. 

Yes I already have a better machine so that is not the answer I am looking for!  I simply want to understand the problem so that I can fix it, more to satisfy the challenge than a need for yet another machine.

[LesD]

Well this evening I bit the bullet and swapped the two diodes on the Jetway mobo that are down by the CMOS battery. I pulled two from another old mobo and used those rather than two from my tin of old semiconductors. I put a new CR2032 CMOS battery in when I had the mobo re-installed and everything connected up again. To my relief I could still get into the BIOS and configure settings plus it all booted up again as it was doing previously from my W'98 startup floppy disk. All the drives were there and the settings in the BIOS remained after the machine had been switched off for a little while so the CMOS battery was working.   

Only time will tell if this has fixed the premature discharge problem so I have my fingers crossed.

Changing these diode was a fiddly task and they are normal sized components. I needed my strongest glasses and a steady hand. Some of the nearby PCB tracks were like threads. It's not one of my neatest jobs but the mobo does still work and with a bit of luck it may have fixed the problem. 

I did compare the forward and reverse resistance of the replacement diodes with those of the ones that I took out and there was certainly a difference. The reverse resistance of the replacements was much higher so hopefully it will follow that the leakage will be less. 

What do you reckon, I am in with a chance or not?   

[patio]

As you stated...only time will tell.

[LesD]

As you stated...only time will tell.

Sadly for me time was not kind and the battery started to fail prematurely once again!