I just purchased a 98 F3. The battery was dead so I replaced it. A week later out of nowhere, ,the battery died. I was unable to push start it, so we jumped it. Evern then, it was very weak. So, I replaced the battery again (under warranty). I took her for a cruise today (maybe 30 miles) and she died again. I was able to push start it and now it seems fine.
I have done a search and it looks like this is a rectifier problem. Does this sound right? Where is the rectifier located? Is there anyway to test it? Thanks

 

yes that sounds like its the problem.

here is a way to diagnose for sure http://cbrworld.net/forums/thread/140473.aspx

the regulator is locate don the right side under neath the rear side fairing . i believe its bolted to your subframe.

 

Yeppers... that sucks. Watch for blown fuses too!

 

Yep thats what it is. They are known for going bad on these bikes. I just had to replace mine. $45 on ebay